[{"data":1,"prerenderedAt":1036},["ShallowReactive",2],{"layer:exploration:investigate":3},{"layer":4,"contentHash":1015,"dependencyHashes":1016,"approval":1030,"releaseId":1035},{"schemaVersion":5,"conceptId":6,"locale":7,"depth":8,"revision":5,"title":9,"subtitle":10,"summary":11,"objectives":12,"estimatedMinutes":18,"plate":19,"blocks":43,"sourceIds":1010,"reviewStatus":1011,"authoring":1012},1,"exploration","en","investigate","Predict it, try it, compare it, test it","Lab-heavy investigations that check what the Discover layer told you","Compare stated reasons with actual results for Columbus and Zheng He, run a monsoon 'what if', judge whether one number sums up a disputed history, sort evidence against a claim about da Gama, read a paraphrased passage from two sides, and test sweeping generalisations against real voyages.",[13,14,15,16,17],"Compare a voyage's stated reason with what actually happened, and describe the gap, for at least two voyages.","Use a 'what if' question to test whether you understand why a route or timetable worked the way it did.","Judge a historical claim by sorting evidence into supports, contradicts, not relevant and uncertain.","Read a paraphrased passage from more than one angle and say whose viewpoint it centres.","Test broad claims about exploration against real examples, and explain why one counterexample is enough to break an 'always' claim.",40,{"title":20,"rows":21},"Lesson plate",[22,25,28,31,34,37,40],{"label":23,"value":24},"Depth","Investigate",{"label":26,"value":27},"Reading time","≈ 40 minutes",{"label":29,"value":30},"Prior knowledge","Discover layer of this topic",{"label":32,"value":33},"Chapters","9",{"label":35,"value":36},"Labs","Voyage map, data lab, evidence sort, passage, sort game",{"label":38,"value":39},"Focus","Predict, try, compare, test",{"label":41,"value":42},"Numbers","All computed and asserted; contested ones stay ranges",[44,50,54,60,108,113,116,139,157,170,175,181,185,208,213,216,342,355,376,391,396,399,442,456,461,466,471,483,488,491,540,545,566,571,574,617,638,641,646,649,662,675,693,697,718,772,776,781,784,799,812,816,829,832,837,866,987,999],{"id":45,"type":46,"title":47,"eyebrow":48,"navLabel":49},"ch01","chapter","How this layer works: predict, then test","Chapter 01","1 Predict & test",{"id":51,"type":52,"markdown":53},"intro-investigate","prose","The Discover layer told you what happened. This layer asks a harder question: **how do you know that what you were told is the whole story?**\n\nEvery chapter here works the same way. You will meet a claim, a route, a set of numbers or a passage of text. Before you are shown the answer, you will be asked to **predict** it. Then you will **try** a lab, **compare** two things that look similar but are not, and **test** whether a big, confident-sounding sentence is actually true every single time.\n\nThis is exactly what historians do. Nobody hands them a finished textbook. They start with scraps: a ship's log, a customs ledger, nine different population guesses that disagree with each other, and they have to work out what is solid and what is not.",{"id":55,"type":56,"variant":57,"title":58,"markdown":59},"obs-four-moves","callout","observation","Four moves, used all through this layer","- **Predict.** Commit to an answer before you see it. A guess you can be wrong about teaches you more than a fact you just read.\n- **Try.** Use a lab: move the numbers, sort the cards, follow the route.\n- **Compare.** Put two voyages, two datasets or two sides of a page next to each other, on purpose.\n- **Test.** Take a sentence with the word \"always\" or \"every\" in it and go looking for the one case that breaks it.",{"id":61,"type":62,"title":63,"prompt":64,"options":65},"explorer-four-moves","explorer","What each chapter will ask of you","Pick a move to see the kind of question it leads to.",[66,78,88,98],{"id":67,"label":68,"chain":69,"badge":74,"note":77},"predict","Predict",[70,71,72,73],"A claim or route appears","You commit to an answer","You see what really happened","You measure the gap",{"text":75,"tone":76},"Used in chapters 2, 3 and 7","yes","A prediction is graded by honesty, not by being right. Chapter 2 asks you to predict whether Columbus ever admitted his mistake. Chapter 3 asks you to predict what a delayed monsoon would do to a fleet's plans.",{"id":79,"label":80,"chain":81,"badge":85,"note":87},"try","Try",[82,83,84],"A lab appears","You move things around","A pattern appears you'd otherwise miss",{"text":86,"tone":76},"Five labs in this layer","You will route four real voyages on one map, edit two real datasets, sort nine pieces of evidence against one claim, and sort nine sweeping statements into always, sometimes and not true.",{"id":89,"label":90,"chain":91,"badge":95,"note":97},"compare","Compare",[92,93,94],"Two things that look alike","Placed side by side on purpose","The real difference shows up",{"text":96,"tone":76},"The centrepiece of chapter 2","Columbus and Zheng He both set out with a stated reason and a plan. What happened next could hardly have been more different, and comparing them side by side is the fastest way to see why.",{"id":99,"label":100,"chain":101,"badge":105,"note":107},"test","Test",[102,103,104],"A sentence says 'always' or 'every'","You hunt for one exception","One exception breaks it completely",{"text":106,"tone":76},"The whole of chapter 7","\"Every voyage was funded by a king.\" \"The explorer named in the book was always first to arrive.\" \"A bigger fleet always did better.\" Each of these sounds reasonable until you check it against a single real case.",{"id":109,"type":46,"title":110,"eyebrow":111,"navLabel":112},"ch02","Compare: stated reason vs actual result","Chapter 02","2 Reason vs result",{"id":114,"type":52,"markdown":115},"compare-intro","Here is the comparison this whole layer is built around. Two voyages, thirteen years apart, both funded on a clear stated reason. One reached the place it aimed for, technically, and was still stopped. The other missed its target completely, and the man in charge never admitted it.\n\nRead the stated reason for each one. **Guess what you think happened next, before you look at the next column.** Then read the actual result, and look for the gap between the two.",{"id":117,"type":118,"caption":119,"columns":120,"rows":126},"table-reason-vs-result","table","Two voyages, stated reason against actual result",[121,122,123,124,125],"Voyage","Stated reason","What was predicted","What actually happened","The gap",[127,133],[128,129,130,131,132],"**Columbus**, 1492","Sail west to reach Asia directly, avoiding the overland and Red Sea middlemen, and bring back spices, gold and converts.","Land in Japan or China after a few thousand kilometres, based on his own, far too small, estimate of the Earth's size.","After 36 days of open ocean from the Canaries he reached Caribbean islands, about 20,000 km short of Asia by the real distance. He died in 1506 still describing the region as the edge of Asia.","He aimed at a known place using a wrong map of the world, hit an unknown place, and insisted for the rest of his life that the two were the same.",[134,135,136,137,138],"**Zheng He**, 1405-1433","Show the Ming emperor's power, collect tribute, carry envoys, and trade in silk and porcelain, under direct orders from the throne.","That large, well-organised fleets could reach the Indian Ocean's great ports and return safely with tribute and prestige.","Seven fleets did reach Calicut, Hormuz and the east African coast, safely, repeatedly, across almost three decades (28 years). By that narrow measure the mission worked every single time.","The gap is not at sea. It is back home: the Ming court judged the cost not worth it, stopped funding new fleets in 1433, and let the ships rot.",{"id":140,"type":141,"prompt":142,"options":143,"explanation":156},"pred-columbus-belief","prediction","Columbus made four voyages across the Atlantic and lived another fourteen years after the first one, exploring much of the Caribbean and part of South America. Predict: did he ever accept that these lands were not part of Asia?",[144,147,150,153],{"id":145,"label":146},"a","Yes, he corrected himself after the second voyage",{"id":148,"label":149},"b","Yes, but only in a private letter, never in public",{"id":151,"label":152},"c","No. He insisted to his death in 1506 that he had reached the edge of Asia",{"id":154,"label":155},"d","The question never came up; nobody at the time cared where he had landed","**c.** Even as later navigators mapped a long, separate coastline that did not match anything in Asia, Columbus kept adjusting his own theory rather than his conclusion. It is a useful reminder that being wrong about a big claim and *admitting* you were wrong are two completely different events, and the second one does not always happen.",{"id":158,"type":141,"prompt":159,"options":160,"explanation":169},"pred-zheng-stop","Zheng He's fleets reached the Indian Ocean's great ports and returned home successfully, again and again, for almost thirty years. Predict: what happened after the seventh voyage, in 1433?",[161,163,165,167],{"id":145,"label":162},"The fleets kept sailing and eventually reached Europe by sea",{"id":148,"label":164},"The Ming court stopped funding new fleets, and the ships were left to rot",{"id":151,"label":166},"A single storm destroyed the whole fleet at sea",{"id":154,"label":168},"Zheng He was declared emperor and ended the voyages himself","**b.** Nothing at sea forced this. The court weighed the cost of vast fleets against troubles on China's northern land border and chose to spend there instead. It is worth sitting with: **China had the ships, the charts and the skill to keep going. Stopping was a decision, not a failure.**",{"id":171,"type":56,"variant":172,"title":173,"markdown":174},"aha-two-gaps","aha","Two different shapes of gap","Columbus's gap is a gap in **knowledge**: he was wrong about where he was, and stayed wrong. Zheng He's gap is a gap in **will**: the fleets worked exactly as planned, and a later decision, made in a palace and not on a ship, ended them anyway.\n\nNeither gap shows up if you only ask \"did the voyage succeed?\" You have to ask **succeed at what, judged by whom, and for how long?**",{"id":176,"type":177,"conceptId":178,"relation":179,"explanation":180},"conn-power-decision","connection","government-india","related_to","Whether a ruler keeps funding a costly project, the way the Ming court stopped Zheng He's fleets, is a decision about the use of state power and money, the same kind of question explored in how a government decides what to spend on.",{"id":182,"type":183,"prompt":184},"reflect-third-voyage","reflection","Pick a third voyage from this topic: either Vasco da Gama (1497-98) or Magellan and Elcano (1519-22). Fill in the same four boxes for it: stated reason, what was predicted, what actually happened, and the gap between the two. Then write one sentence saying which of your three voyages, Columbus, Zheng He or your choice, has the widest gap, and why you judged it that way.",{"id":186,"type":187,"itemId":188,"prompt":189,"check":190,"hints":202,"feedback":205},"p-gap-columbus","practice","exploration.investigate-gap-columbus","Which sentence best captures the *gap* between Columbus's stated reason and what actually happened?",{"kind":191,"options":192,"correct":201},"choice",[193,195,197,199],{"id":145,"label":194},"He aimed for Asia, miscalculated the distance badly, arrived somewhere else entirely, and insisted for the rest of his life that he had succeeded",{"id":148,"label":196},"He aimed for the Caribbean all along and reached it exactly as planned",{"id":151,"label":198},"The voyage was a pure accident; he never intended to sail anywhere in particular",{"id":154,"label":200},"The gap is that his ships were too small to survive the crossing",[145],[203,204],"Compare the 'stated reason' and 'what actually happened' columns in the table above.","The gap is about a belief that did not change, not about the ships.",{"correct":206,"incorrect":207},"Right. He set a target, was badly wrong about the geography, and then kept the wrong belief rather than update it, even as more of the coastline was mapped by others.","Look again at the table. His stated reason was Asia; his result was the Caribbean; and the interesting fact is that he never updated his belief, even years later.",{"id":209,"type":46,"title":210,"eyebrow":211,"navLabel":212},"ch03","Try: what if the wind changed?","Chapter 03","3 What if the wind",{"id":214,"type":52,"markdown":215},"whatif-intro","A \"what if\" question is a good test of understanding. If you only memorised that the monsoon runs on a timetable, you cannot answer one. If you understand *why* it runs on a timetable, you can work out what would change if the timetable shifted.\n\nThe lab below places four real voyages on one map. Notice that only one of them, da Gama's, has a monsoon leg at all. Columbus, Magellan and Cook sailed oceans with no seasonal wind switch of that kind, which is itself worth noticing: **the monsoon is not a feature of all oceans, it is a feature of the Indian Ocean's geography.**",{"id":217,"type":218,"component":219,"componentVersion":5,"config":220,"objective":340,"textAlternative":341},"lab-map-whatif","interactive","voyage-map",{"voyages":221,"showWinds":339},[222,246,276,310],{"id":223,"label":224,"year":225,"from":226,"to":227,"path":228,"why":244,"consequence":245},"columbus","Columbus sails west","1492","Palos","the Caribbean",[229,232,235,238,241],[230,231],37.23,-6.9,[233,234],28.1,-15.41,[236,237],25,-40,[239,240],24,-74.5,[242,243],19,-70,"Columbus believed Asia lay a short sail west and persuaded the Spanish crown to pay for it. He wanted a spice route, gold, and fame.","He reached islands in the Caribbean and died still believing they were near Asia. His voyages opened the Atlantic to Spanish settlement, and to conquest, disease and slavery.",{"id":247,"label":248,"year":249,"from":250,"to":251,"path":252,"why":274,"consequence":275},"da-gama","Vasco da Gama to Calicut","1497-1498","Lisbon","Calicut",[253,256,259,262,265,268,271],[254,255],38.71,-9.14,[257,258],14.93,-23.51,[260,261],-20,-30,[263,264],-34.36,18.47,[266,267],-15.03,40.73,[269,270],-3.22,40.12,[272,273],11.25,75.78,"Portugal wanted pepper and other spices without paying merchants along the overland route, and wanted to weaken its rivals. The king backed the voyage.","The first sea route from Europe to India. Within twelve years Portugal held Goa, and European companies began to compete, then fight, for control of Indian Ocean trade.",{"id":277,"label":278,"year":279,"from":280,"to":280,"path":281,"why":308,"consequence":309},"magellan","Magellan and Elcano","1519-1522","Sanlucar",[282,285,286,289,291,294,297,300,303,305,306,307],[283,284],36.78,-6.35,[233,234],[287,288],-22.9,-43.2,[290,243],-53.5,[292,293],-10,-140,[295,296],13.44,144.79,[298,299],10.32,123.89,[301,302],0.69,127.4,[261,304],80,[263,264],[257,258],[283,284],"To reach the Spice Islands by sailing west, so Spain could trade in cloves and nutmeg without crossing Portuguese routes.","The first voyage all the way round the world, finished by Elcano after Magellan was killed. It proved the oceans connect, and showed how deadly such a crossing was.",{"id":311,"label":312,"year":313,"from":314,"to":314,"path":315,"why":337,"consequence":338},"cook","Cook's first Pacific voyage","1768-1771","Plymouth",[316,319,320,323,326,329,332,335,336],[317,318],50.37,-4.14,[287,288],[321,322],-55.98,-67.27,[324,325],-17.65,-149.42,[327,328],-41.3,174.8,[330,331],-34,151.2,[333,334],-6.2,106.8,[263,264],[317,318],"To observe Venus crossing the Sun from Tahiti, a science problem, and then to look for land in the southern Pacific for Britain.","Careful charts and scientific collections, and the beginning of British claims on lands where Aboriginal and Maori peoples had lived for thousands of years.",true,"Compare four real routes on one map, and ask what would change if the wind that shapes one of them behaved differently.","A world map shows four routes with a wind toggle.\n\n**Columbus** (1492, Palos to the Caribbean): a short, direct Atlantic crossing with the steady trade winds behind him, no monsoon, no seasonal reversal to plan around.\n\n**Da Gama** (1497-98, Lisbon to Calicut): swings deep into the south Atlantic to catch favourable winds round Africa, then joins the Indian Ocean's monsoon system from Malindi onward. This is the only leg on the map where the wind toggle changes anything real.\n\n**Magellan** (1519-22, Sanlucar round the world): crosses three oceans and depends on finding a strait at all, let alone a wind.\n\n**Cook** (1768-71, Plymouth to the Pacific and back): timed around a specific astronomical event, the transit of Venus, rather than a wind season.\n\nFlip the wind toggle and only da Gama's route visibly depends on it. Now imagine a \"what if\": suppose, in a particular year, the monsoon that should turn in June to September was delayed by 6 weeks. A merchant fleet loaded and ready in Aden would simply have to wait, extending its whole year's cycle by 42 days before it could even start the crossing.",{"id":343,"type":141,"prompt":344,"options":345,"explanation":354},"pred-monsoon-shift","Suppose the south-west monsoon, which normally starts blowing about June to September, does not begin until two months later than usual in one particular year. A fleet of merchant ships is loaded and ready to leave Aden on the normal date. What happens to their plans?",[346,348,350,352],{"id":145,"label":347},"Nothing changes; the ships leave exactly on schedule",{"id":148,"label":349},"They must wait in port for the wind, which pushes back their whole year's trading cycle",{"id":151,"label":351},"They simply switch to the north-east monsoon instead, going the same direction",{"id":154,"label":353},"The delay makes no difference because ships in 1498 had engines","**b.** The wind, not the calendar, decides when a sailing ship can leave. A two-month delay does not just cost two months at the start; it can push the return leg past the point where the opposite monsoon is ready, meaning an even longer wait, or a dangerous late crossing. This is exactly why port cities such as Calicut and Aden grew rich on warehousing and lending: waiting was normal, and somebody had to look after the goods and the sailors while it happened.",{"id":356,"type":357,"tone":358,"items":359},"spec-whatif-monsoon","spec","amber",[360,364,368,372],{"label":361,"big":362,"value":363},"Normal start","June to September","The usual window for the south-west monsoon to begin blowing towards India.",{"label":365,"big":366,"value":367},"Delayed start","8 weeks later","The hypothetical delay used in the prediction above.",{"label":369,"big":370,"value":371},"Extra wait","42 days","6 weeks converted to days: 6 × 7 = 42.",{"label":373,"big":374,"value":375},"Normal Calicut wait","≈ 108 days","How long a ship arriving in August already waits for the return wind, even with no delay at all.",{"id":377,"type":187,"itemId":378,"prompt":379,"check":380,"hints":385,"feedback":388},"p-monsoon-shift","exploration.investigate-monsoon-shift","A ship's captain normally waits about 108 days in Calicut for the return wind. If the return monsoon this year is delayed by exactly 6 weeks, how many *extra* days beyond the usual wait must the captain plan for?",{"kind":381,"answer":382,"tolerance":383,"unit":384},"number",42,0,"days",[386,387],"6 weeks is being asked for, not the whole wait.","One week is 7 days.",{"correct":389,"incorrect":390},"Right: 6 × 7 = **42 extra days**. Notice the question only asked for the *extra* delay, not the new total; reading exactly what is being asked is half of this kind of problem.","Multiply 6 weeks by 7 days. The question asks only for the extra delay, not the full new waiting time.",{"id":392,"type":46,"title":393,"eyebrow":394,"navLabel":395},"ch04","Try: does one number tell you enough?","Chapter 04","4 One number enough?",{"id":397,"type":52,"markdown":398},"data-intro","Two datasets, both genuine spreads that historians actually work with. The first is nine different published estimates of how many people lived in the Americas in 1492. The second is how many days five real voyages spent with no land in sight at all.\n\nBefore you touch the lab, ask yourself: if a book gave you only the **mean** of nine wildly different guesses, what would you be missing?",{"id":400,"type":218,"component":401,"componentVersion":5,"config":402,"objective":440,"textAlternative":441},"lab-data-investigate","data-lab",{"datasets":403,"valueRange":423,"step":425,"challenges":426},[404,416],{"label":405,"values":406,"unit":415},"Population of the Americas in 1492, published estimates",[407,408,18,409,410,411,412,413,414],8,13,43,54,60,72,100,112,"million",{"label":417,"values":418,"unit":384},"Days out of sight of land, five real voyages",[419,420,421,422,382],36,93,98,68,{"min":383,"max":424},120,5,[427,431,434,436],{"measure":428,"target":429,"prompt":430},"mean",65,"Population dataset: move exactly one of the nine points so the mean rises to about 65 million. Which point moves the mean the most for the smallest change?",{"measure":432,"target":411,"prompt":433},"range","Population dataset: without deleting any point, pull the range down to about 60 million by moving the most extreme point inward.",{"measure":428,"target":304,"prompt":435},"Sea-days dataset: raise the mean of the five voyages to about 80 days by changing only the shortest one.",{"measure":437,"target":438,"prompt":439},"median",90,"Sea-days dataset: push the median up to about 90 days. How many of the five values do you actually need to change to do that?","Edit two real datasets and watch the mean, median and range change, then judge how much a single summary number hides.","Two editable dot plots, one per dataset, each with live mean, median and range and four target challenges.\n\n**Population dataset:** nine published estimates, in millions: [8, 13, 40, 43, 54, 60, 72, 100, 112]. Its mean is about 55.8, its median 54, and its range a huge 104 million, because the low and high estimates use very different methods.\n\n**Sea-days dataset:** [36, 93, 98, 68, 42] days, from five real voyages' open-ocean legs. Mean about 67.4, median 68, range 62.\n\nThe challenges ask you to move points to hit a target mean, range or median, which shows how sensitive each measure is: the mean moves with every point, the median barely moves unless you cross the middle, and the range only cares about the two extremes.",{"id":443,"type":444,"title":445,"problem":446,"steps":447,"help":453},"we-mean-median-range","worked_example","One number, or three, or nine?","Nine historians have published nine different estimates of the population of the Americas in 1492, in millions: **[8, 13, 40, 43, 54, 60, 72, 100, 112]**.\n\nFind the mean, median and range. Then say what a reader loses if a book reports only one of these three.",[448,449,450,451,452],"Mean = sum ÷ count. Adding the nine values and dividing by 9 gives **55.8 million**.","Median = the middle value once they are sorted: [8, 13, 40, 43, 54, 60, 72, 100, 112]. The middle (5th of 9) value is **54 million**.","Range = highest − lowest = 112 − 8 = **104 million**.","The mean (about 56) and the median (54) are fairly close to each other, which sounds reassuring.","But the range of 104 million tells a different story: the highest published estimate is more than **14 times** the lowest. A single 'about 56 million' hides a genuine, unresolved argument among historians about method, not just rounding.",{"simplerExplanation":454,"anotherExample":455},"Add them and divide for the mean. Line them up and find the middle one for the median. Subtract smallest from biggest for the range. The mean and median can look tidy even when the range shows real disagreement underneath.","Five friends guess a jar has 20, 22, 21, 19 and 100 sweets. The mean is dragged up to 36.4 by one wild guess, while the median, 21, is a much better single summary here. Always check the range before trusting a mean.",{"id":457,"type":56,"variant":458,"title":459,"markdown":460},"nuance-mean-hides","nuance","A tidy average can hide a real argument","The mean and median for the Americas' 1492 population are close together and look sensible. That closeness does not mean historians agree. It means the middle of a wide, genuinely disputed range happens to sit near the middle. Always check the **range** and ask *why* it is that wide before treating an average as settled fact.",{"id":462,"type":56,"variant":463,"title":464,"markdown":465},"model-limit-datalab","model_limit","What the lab cannot show you","The lab shows you the shape of the numbers: mean, median, range. It cannot show you *why* the nine estimates differ, which is the more important question. That comes from reading how each historian counted: from farmland area and crop yields, from tax records made decades later, from disease models, from the size of cities described in early accounts. Different assumptions in that reasoning, not carelessness, produce the spread.",{"id":467,"type":177,"conceptId":468,"relation":469,"explanation":470},"conn-data-handling","data-handling","helps_understand","Choosing whether a mean, median or range best represents a set of numbers, and knowing that a tidy average can still hide real disagreement, is exactly the reasoning taught in data handling.",{"id":472,"type":187,"itemId":473,"prompt":474,"check":475,"hints":477,"feedback":480},"p-mean-median","exploration.investigate-mean-median","The five sea-days values are [36, 93, 98, 68, 42]. What is the range of this dataset?",{"kind":381,"answer":476,"tolerance":383,"unit":384},62,[478,479],"Range = highest value − lowest value.","The highest is 98 and the lowest is 36.",{"correct":481,"incorrect":482},"Right: 98 − 36 = **62 days**. That is a big spread for only five voyages, showing how differently 'crossing an ocean' can go.","Subtract the smallest value from the largest: 98 − 36.",{"id":484,"type":46,"title":485,"eyebrow":486,"navLabel":487},"ch05","Test a claim: did da Gama open the ocean?","Chapter 05","5 Did he open it?",{"id":489,"type":52,"markdown":490},"evidence-intro","Here is a claim you will meet, in some form, in a great many books:\n\n**\"Vasco da Gama's 1498 voyage single-handedly opened Indian Ocean trade to the world.\"**\n\nIt sounds definite. Some of it is true. Some of it is not. The only honest way to judge it is to gather evidence and sort it, piece by piece, rather than accept or reject the whole sentence at once.",{"id":492,"type":218,"component":493,"componentVersion":5,"config":494,"objective":538,"textAlternative":539},"lab-evidence-dagama","evidence-sort",{"claim":495,"categories":496,"items":501},"Vasco da Gama's 1498 voyage single-handedly opened Indian Ocean trade to the world.",[497,498,499,500],"supports","contradicts","not_relevant","uncertain",[502,506,510,514,518,522,526,530,534],{"id":503,"text":504,"category":498,"explanation":505},"e1","Arab, Gujarati and Swahili sailors had already traded across the Indian Ocean for over 1,000 years before 1498, using the monsoon winds.","This directly undercuts the word 'opened': a busy trading world already existed.",{"id":507,"text":508,"category":498,"explanation":509},"e2","A Greek merchant's handbook to this ocean, the Periplus, was written about 1,400 years before da Gama's voyage.","Written proof of an organised trading world long predating 1498.",{"id":511,"text":512,"category":498,"explanation":513},"e3","Da Gama needed a local pilot hired at Malindi to cross the Arabian Sea, because his own crew did not know the route.","If the ocean needed 'opening', he would not have needed someone who already knew the way across it.",{"id":515,"text":516,"category":498,"explanation":517},"e4","Chinese fleets under Zheng He had already sailed to Calicut and the east African coast in the early 1400s, decades before any Portuguese ship.","Another sea power had already reached the same ports from the opposite direction.",{"id":519,"text":520,"category":497,"explanation":521},"e5","Before 1498, no ship had sailed directly from Europe to India by sea; goods travelled instead through Arab, Egyptian and Venetian middlemen.","This is the narrow, accurate part of the claim: a *direct European sea link* really was new.",{"id":523,"text":524,"category":497,"explanation":525},"e6","Da Gama's voyage created the first continuous sea route between Europe and India, sailed start to finish by one crew.","Also true and specific: it removed several of the middlemen from that one path.",{"id":527,"text":528,"category":499,"explanation":529},"e7","The Zamorin's court in Calicut considered da Gama's gifts poor compared with what other merchants usually brought.","This is about how the visit was received, not about whether trade itself was newly 'opened'.",{"id":531,"text":532,"category":499,"explanation":533},"e8","Vasco da Gama was Portuguese, and Portugal later built armed trading posts along the Indian Ocean coast.","His nationality and later Portuguese forts do not, by themselves, prove anything about who opened trade in 1498.",{"id":535,"text":536,"category":500,"explanation":537},"e9","Within a few decades, Portuguese ships tried to control Indian Ocean trade by force, demanding passes from other ships or attacking them.","This shows Portugal changed the ocean's trade a great deal, but by force, later, and differently from simply 'opening' it. Reasonable people can disagree about whether this counts as evidence for the claim.","Sort nine pieces of evidence against one confident claim, and see how much of it survives.","Nine short statements must be sorted into **supports**, **contradicts**, **not relevant** and **uncertain**, against the claim that da Gama single-handedly opened Indian Ocean trade to the world.\n\nMost of the strongest evidence contradicts the claim as stated: the monsoon trade, the Periplus, the hired pilot and Zheng He's earlier fleets all show a busy ocean that needed no opening. Two pieces genuinely support a narrower version of the claim: da Gama did create the first direct sea link from Europe. Two are not relevant to the claim either way. One, about later Portuguese force, is genuinely uncertain and worth arguing about.\n\nThe lesson of the game: **the claim survives only if you shrink it.** \"Opened a new direct link from Europe\" is true. \"Opened Indian Ocean trade to the world\" is not.",{"id":541,"type":56,"variant":542,"title":543,"markdown":544},"misconception-opened","misconception","\"Opened\" is doing a lot of work in that sentence","Notice how one verb can smuggle in a much bigger claim than the facts support. \"Opened\" suggests something that did not exist before. What actually happened is closer to **\"joined\"**: an existing, thousand-year-old trading system gained one new, direct connection from Europe. Watch for this trick in other sentences too: \"discovered\", \"founded\" and \"civilised\" all carry the same hidden assumption that nothing was there before.",{"id":546,"type":187,"itemId":547,"prompt":548,"check":549,"hints":560,"feedback":563},"p-evidence-claim","exploration.investigate-evidence-claim","Based on the evidence you sorted, which single word most honestly replaces 'opened' in the original claim?",{"kind":191,"options":550,"correct":559},[551,553,555,557],{"id":145,"label":552},"Invented",{"id":148,"label":554},"Joined",{"id":151,"label":556},"Ended",{"id":154,"label":558},"Discovered",[148],[561,562],"Most of the strongest evidence shows a trading world that already existed.","What was genuinely new was a direct connection, not the trade itself.",{"correct":564,"incorrect":565},"**Joined.** Da Gama connected Europe directly to a trading world that had been running for well over a thousand years. That is real and worth knowing; it is just a smaller and more honest claim than 'opened'.","Look at how many pieces of evidence contradicted the idea that the ocean needed opening at all. What was new was a connection, not the existence of trade.",{"id":567,"type":46,"title":568,"eyebrow":569,"navLabel":570},"ch06","Compare: whose voice, whose gaze?","Chapter 06","6 Whose gaze?",{"id":572,"type":52,"markdown":573},"passage-intro","Almost everything written about the meeting at Calicut in 1498 comes from the Portuguese side: sailors, chroniclers and, later, historians working from Portuguese sources. That does not make it false. It does mean every sentence needs one extra question asked of it: **whose eyes was this written through?**\n\nThe passage below is **not a direct quotation from any single document**. It is a short paraphrase, built from the general shape of several historical accounts of the gift-giving at Calicut, written so you can practise spotting whose viewpoint controls a piece of writing, without pretending it is a word-for-word record.",{"id":575,"type":218,"component":576,"componentVersion":5,"config":577,"objective":615,"textAlternative":616},"lab-passage-zamorin","annotated-passage",{"title":578,"techniques":579,"segments":592,"context":614},"At the Zamorin's court, May 1498",[580,584,588],{"id":581,"label":582,"description":583},"viewpoint","Whose viewpoint?","Ask who is telling this part of the story, and what they could actually see or hear for themselves.",{"id":585,"label":586,"description":587},"left-out","What's left out?","Notice names, feelings or reasons for actions that this account simply does not mention.",{"id":589,"label":590,"description":591},"other-side","The other side","Imagine what the missing side would have said about the very same moment.",[593,596,601,606,611],{"id":594,"text":595},"seg1","The Portuguese fleet's captain was brought before the ruler of Calicut, the Zamorin, and presented gifts chosen to represent the best his country could offer: striped cloth, red hats, strings of coral, sugar, oil and honey.",{"id":597,"text":598,"annotation":599},"seg2","According to the Portuguese accounts, officials at the court looked over the gifts and remarked, not unkindly but plainly, that the poorest merchant arriving from Mecca usually brought finer things.",{"technique":581,"note":600},"This sentence survives because a Portuguese writer recorded his own side's embarrassment. We have no matching sentence recorded by anyone who actually stood in the Zamorin's court that day.",{"id":602,"text":603,"annotation":604},"seg3","The captain is described as having expected a warmer welcome, given the distance and difficulty of the voyage that had brought him there.",{"technique":585,"note":605},"The passage never gives us the Zamorin's own reasoning: what he expected from a new arrival, what treaties or customs already governed foreign merchants in his busy port, or what his own advisors told him privately.",{"id":607,"text":608,"annotation":609},"seg4","Within a few years, the captain returned with warships instead of gifts, and future encounters were negotiated at the point of a cannon rather than across a table.",{"technique":589,"note":610},"A Calicut chronicle, had one survived in the same detail, might have opened very differently: with a description of a rich, well-run port used to dealing with merchants from a dozen nations, receiving a poorer newcomer whose behaviour later turned openly hostile.",{"id":612,"text":613},"seg5","Historians rely on the Portuguese version because it is the version that was written down and kept.","A paraphrase based on the general shape of several historical accounts, not a verbatim quotation from any one document.","Read a short paraphrased scene and annotate it for whose viewpoint controls it, what is missing, and what the other side might have said.","Five short segments describe the gift-giving at Calicut in May 1498. The passage is explicitly a paraphrase, not a real quotation.\n\nThree segments are annotated. One shows that even an embarrassing detail survives only because the Portuguese side chose to record it: **whose viewpoint** controls what we know. One points out that the Zamorin's own reasoning is never given at all: **what's left out**. One imagines how a matching account from Calicut's side might have opened very differently: **the other side**.\n\nThe point of the lab is not to decide the Portuguese account is dishonest. It is to notice that **one surviving version, however careful, is still only one version**, and to practise asking the three questions of any historical passage you meet from now on.",{"id":618,"type":187,"itemId":619,"prompt":620,"check":621,"hints":632,"feedback":635},"p-passage-viewpoint","exploration.investigate-passage-viewpoint","This passage survives mainly through Portuguese accounts. What is the single most useful question to ask before treating it as the full story?",{"kind":191,"options":622,"correct":631},[623,625,627,629],{"id":145,"label":624},"Is the writing well spelled?",{"id":148,"label":626},"Whose account is this, and what could that person actually see or hear?",{"id":151,"label":628},"Was the ship large enough to carry the gifts?",{"id":154,"label":630},"Did the meeting happen on a sunny day?",[148],[633,634],"Think about which of the three annotation techniques matters most for judging reliability.","The passage never claims to be neutral; it claims to be one side's record.",{"correct":636,"incorrect":637},"**b.** Every account was made by someone, for some purpose, with access to only part of the scene. Asking that question first is how you decide what weight to give the rest.","The useful question is about the source of the account, not about the weather or the spelling. Reread the 'whose viewpoint' annotation.",{"id":639,"type":183,"prompt":640},"reflect-other-side","Using only claims you can support from this topic, write two or three sentences describing the same gift-giving scene from the point of view of an official at the Zamorin's court. Do not invent specific names or dialogue that were not given to you; describe what such an official would likely have noticed and thought, based on what you know about Calicut being a rich, established trading port.",{"id":642,"type":46,"title":643,"eyebrow":644,"navLabel":645},"ch07","Test: is it always true?","Chapter 07","7 Always true?",{"id":647,"type":52,"markdown":648},"always-intro","A \"sometimes\" claim survives one counterexample. An \"always\" claim does not: **one solid exception is enough to break it completely.** This chapter puts three big, confident-sounding sentences about exploration to exactly that test.",{"id":650,"type":141,"prompt":651,"options":652,"explanation":661},"pred-king-funded","\"Every voyage of exploration was funded by a king or a queen.\" True or false?",[653,655,657,659],{"id":145,"label":654},"True: no voyage could happen without a monarch's money",{"id":148,"label":656},"False: some voyages were funded by trading companies, merchants, or the traveller's own resources and hospitality",{"id":151,"label":658},"True, but only for European voyages",{"id":154,"label":660},"False: no ruler ever funded a voyage","**b.** Zheng He's fleets and Columbus's crossing were state-funded, so the claim looks true if you only look at those two. But Ibn Battuta travelled for 29 years on a mixture of his own means, gifts from rulers he visited, and paid work as a judge along the way; he was never sent by a single monarch with a single order. Later, whole trading companies (chartered by governments but funded by investors) paid for voyages, which is a different thing from a royal treasury. One real exception is enough: the \"every\" in the sentence fails.",{"id":663,"type":141,"prompt":664,"options":665,"explanation":674},"pred-first-arrival","\"The explorer named in a history book was always the first human being to reach that place.\" True or false?",[666,668,670,672],{"id":145,"label":667},"True: that is what makes them an explorer",{"id":148,"label":669},"False: in almost every case in this topic, other people, often organised traders or navigators, had already been there",{"id":151,"label":671},"True for the Americas but false everywhere else",{"id":154,"label":673},"False, but only for places in the Pacific","**b.** Columbus reached islands where Taino people already lived. Da Gama reached a coast that Arab, Gujarati and Swahili traders had sailed to for centuries, and Zheng He's fleets had already visited decades earlier. Cook charted Pacific islands that Polynesian navigators had reached, using their own careful star and wave-reading methods, over a thousand years before. \"First\" in these books almost always means \"first person from that particular writer's own country or culture\", not first human being.",{"id":676,"type":118,"caption":677,"columns":678,"rows":682},"table-fleet-outcomes","Bigger fleet, better outcome? Two real cases",[121,679,680,681],"Fleet size","What happened to the fleet","Did the voyage 'succeed'?",[683,688],[684,685,686,687],"**Zheng He**, first voyage","About 317 ships and 27,800 men, by far the largest fleet in this topic","Reached its destinations safely and repeatedly across seven voyages, with no catastrophic loss recorded","Yes, at sea, every time. No, back home: funding was cut and the fleets were never sent again",[689,690,691,692],"**Magellan and Elcano**","5 ships and about 270 men, a small fleet by comparison","Reduced to one ship and 18 men by the time it reached home; Magellan himself was killed on the way","Yes, on the one measure history remembers it for: it proved a ship could sail all the way round the world",{"id":694,"type":56,"variant":542,"title":695,"markdown":696},"misconception-bigger-better","\"A bigger fleet always did better\"","Zheng He's fleet was roughly **100 times** the size of Magellan's, and it is the smaller fleet's outcome that is remembered as one of the great feats of the whole era. Fleet size predicts how much a voyage can carry and how safely, but it says nothing about whether the political will behind it lasts, or about what counts as \"success\" in the first place.",{"id":698,"type":187,"itemId":699,"prompt":700,"check":701,"hints":712,"feedback":715},"p-bigger-fleet","exploration.investigate-bigger-fleet","Given the table above, what is the fairest conclusion about fleet size and success?",{"kind":191,"options":702,"correct":711},[703,705,707,709],{"id":145,"label":704},"Bigger fleets always succeeded and smaller ones always failed",{"id":148,"label":706},"Fleet size affected what a voyage could carry and how safely, but 'success' depends on what you are measuring and who decides to keep funding it",{"id":151,"label":708},"Fleet size made no difference to anything",{"id":154,"label":710},"Only fleets of exactly five ships ever succeeded",[148],[713,714],"Zheng He's much bigger fleet worked perfectly at sea and was still stopped.","Magellan's tiny surviving crew still achieved the thing it is remembered for.",{"correct":716,"incorrect":717},"**b.** This is the whole point of testing a generalisation: 'bigger is better' is not false everywhere, but it is not true everywhere either, and the real answer depends on defining what 'better' means before you can measure it.","Reread both rows of the table. One fleet was huge and safe but was stopped by a decision at home; one fleet was small and lost badly, but still achieved the goal it is remembered for.",{"id":719,"type":218,"component":720,"componentVersion":5,"config":721,"objective":770,"textAlternative":771},"lab-sort-generalisations","sort-game",{"prompt":722,"bins":723,"items":733,"seconds":383},"Sort each sweeping statement about exploration: is it always true, sometimes true, or not true as stated?",[724,727,730],{"id":725,"label":726},"always","Always true",{"id":728,"label":729},"sometimes","Sometimes true",{"id":731,"label":732},"nottrue","Not true as stated",[734,738,742,746,750,754,758,762,766],{"id":735,"label":736,"bin":731,"why":737},"g1","Every voyage of exploration was paid for by a king or queen","Ibn Battuta funded much of his own travel; later companies and merchants funded many voyages too.",{"id":739,"label":740,"bin":725,"why":741},"g2","The Indian Ocean monsoon reverses direction roughly twice a year","This is a physical fact about the wind system, checked and used by sailors for well over a thousand years.",{"id":743,"label":744,"bin":731,"why":745},"g3","The explorer named in a textbook was always the first human being to reach that place","Monsoon traders, Zheng He's fleets and Polynesian navigators had already reached many of these places.",{"id":747,"label":748,"bin":731,"why":749},"g4","A bigger fleet always achieved more than a smaller one","Zheng He's huge fleet was stopped by a political decision; Magellan's tiny surviving crew still completed the first voyage round the world.",{"id":751,"label":752,"bin":728,"why":753},"g5","A long ocean crossing lost at least part of its crew","Magellan's crew was reduced by more than 90%. Other, shorter or better-provisioned voyages returned with most or all of their crew.",{"id":755,"label":756,"bin":731,"why":757},"g6","Every explorer reached the place they originally intended to reach","Columbus never reached Asia as intended; Cabral, sailing for India, swung so far west he reached Brazil by accident.",{"id":759,"label":760,"bin":731,"why":761},"g7","A magnetic compass told a sailor exactly where their ship was","A compass gives direction only. Ships still needed the Pole Star, dead reckoning and local pilots to judge position.",{"id":763,"label":764,"bin":728,"why":765},"g8","Rulers on the shore always welcomed a new fleet the same way","The Zamorin's court found da Gama's gifts poor; other meetings in this topic, such as Zheng He's tribute exchanges, went far more smoothly.",{"id":767,"label":768,"bin":725,"why":769},"g9","Every voyage in this topic depended on knowledge, tools or people from more than one culture","Chinese compasses, Arab and Indian navigation methods, hired local pilots and borrowed charts appear behind almost every voyage in this whole topic.","Decide, for nine sweeping statements about exploration, whether each one is always true, only sometimes true, or not true as stated.","Nine confident statements drop into **always true**, **sometimes true** and **not true as stated**.\n\nOnly two survive as **always true**: the monsoon's physical reversal, and the fact that every voyage in this topic leaned on knowledge or people from more than one culture. Four collapse completely once you look for a single exception: royal funding, being first, bigger fleets winning, and reaching the intended destination. Three sit in between, true for some voyages and false for others: crew losses, a compass giving your position, and a warm welcome from the shore.\n\nThe game's real lesson: most textbook-sounding generalisations belong in the middle two bins, not the first one.",{"id":773,"type":56,"variant":458,"title":774,"markdown":775},"nuance-always-word","\"Always\" and \"every\" are expensive words","A sentence that says \"sometimes\" or \"often\" is cheap to defend: one supporting example is enough. A sentence that says \"always\" or \"every\" is expensive: it needs **every single case** to agree, and a reader only needs to find **one** that does not. Before you repeat a confident generalisation, ask whether the word \"always\" is really doing honest work, or just making the sentence sound more impressive than it is.",{"id":777,"type":46,"title":778,"eyebrow":779,"navLabel":780},"ch08","Construct your own hypothetical","Chapter 08","8 Scaling losses",{"id":782,"type":52,"markdown":783},"hypothetical-intro","A good hypothetical is not a guess pulled from nowhere. It takes a real number from one situation and applies it, carefully, to a different one, so you can see the *shape* of a comparison rather than just two isolated facts. Here is one, built and checked with real arithmetic rather than asserted.",{"id":785,"type":444,"title":786,"problem":787,"steps":788,"help":794},"we-scale-zheng-magellan","What if Zheng He's fleet had Magellan's death rate?","Magellan's expedition set out with about **270** men and came home with **18**, a survival fraction of only 18 ÷ 270.\n\nZheng He's first voyage carried about **27,800** men, and recorded no such catastrophe. Purely as a hypothetical, to see the *scale* of the difference: **if** that huge fleet had suffered the same proportion of losses as Magellan's, how many would have come home, and how many would that be in real people?",[789,790,791,792,793],"Find Magellan's survival fraction: 18 ÷ 270 = 0.0667, about 6.7%.","Apply that fraction to Zheng He's fleet: 27,800 × 0.0667 ≈ **1,853 survivors**.","Deaths under this hypothetical: 27,800 − 1,853 = **25,947 people**.","For scale, Zheng He's real fleet was about **103.0** times the size of Magellan's (27,800 ÷ 270 ≈ 103.0).","The real Zheng He voyages did not record losses anywhere near this scale. The hypothetical is not a claim about what happened; it is a tool for feeling the size of the numbers involved when a fleet this large is imagined under Magellan's conditions.",{"simplerExplanation":795,"hints":796},"Take the fraction of Magellan's crew that survived, and imagine applying that same fraction to a much bigger fleet. The point is not that this happened; it is that it shows how enormous the human cost would be if it had.",[797,798],"Work out Magellan's survival fraction first.","Multiply that fraction by Zheng He's crew size to scale it.",{"id":800,"type":801,"items":802},"formulas-scaling","formulas",[803,806,809],{"expression":804,"caption":805},"survival fraction = home ÷ out","Magellan: 18 ÷ 270 ≈ 0.067, about 6.7%.",{"expression":807,"caption":808},"scaled survivors = fraction × new size","Apply one voyage's real survival fraction to a different fleet's size to build an honest hypothetical.",{"expression":810,"caption":811},"27,800 × 0.067 ≈ 1,853","Zheng He's first-voyage crew, scaled by Magellan's real survival fraction.",{"id":813,"type":56,"variant":57,"title":814,"markdown":815},"obs-scale-danger","Why this comparison is worth making","It is easy to read \"18 out of 270 came home\" and \"27,800 men set out\" as two separate facts that live in different chapters. Scaling one onto the other, honestly and with the arithmetic shown, makes the difference in risk between the two voyages impossible to ignore: a fleet 100 times the size, run with careful organisation and repeated safely for thirty years, against a small fleet that came within a whisker of vanishing entirely while still achieving something no one had done before.",{"id":817,"type":187,"itemId":818,"prompt":819,"check":820,"hints":823,"feedback":826},"p-crew-scale","exploration.investigate-crew-scale","Zheng He's first fleet carried about 27,800 men. If, purely as a hypothetical, that fleet had suffered the same survival fraction as Magellan's expedition (18 out of 270), about how many men would this hypothetical scaling say came home?",{"kind":381,"answer":821,"tolerance":413,"unit":822},1853,"men",[824,825],"First find Magellan's survival fraction: 18 ÷ 270.","Then multiply that fraction by 27,800.",{"correct":827,"incorrect":828},"Right, about **1,853**: 27,800 × (18 ÷ 270) ≈ 1,853. Remember, this never actually happened to Zheng He's fleet; it is a constructed comparison to show scale.","Divide 18 by 270 to get a fraction, then multiply that fraction by 27,800.",{"id":830,"type":183,"prompt":831},"reflect-own-hypothetical","Construct one hypothetical of your own, using only real numbers from this topic or its Discover layer. For example: what if Columbus's much smaller crew had faced the Americas' population-loss rate the way Andean mine workers did? State the two real numbers you are combining, do the arithmetic, and write one sentence about what the comparison does and does not tell you.",{"id":833,"type":46,"title":834,"eyebrow":835,"navLabel":836},"ch09","Wrap-up","Chapter 09","9 Wrap-up",{"id":838,"type":839,"title":840,"terms":841},"gloss-investigate","glossary","Words for testing and comparing",[842,846,850,853,856,859,863],{"term":843,"meaning":844,"example":845},"Generalisation","A broad statement meant to cover every case of something, often signalled by words like 'always' or 'every'.","\"Every voyage was funded by a king\" is a generalisation.",{"term":847,"meaning":848,"example":849},"Counterexample","A single real case that breaks a generalisation. One is enough to disprove an 'always' claim.","Ibn Battuta's self-funded travels are a counterexample to 'every voyage was royal'.",{"term":851,"meaning":852},"Hypothetical","A constructed 'what if' scenario, built from real numbers or facts, used to see the shape of a comparison rather than to claim it happened.",{"term":854,"meaning":855},"Paraphrase","A retelling of an account in different words, keeping its general meaning. Not the same as a direct quotation.",{"term":857,"meaning":858},"Primary source","Evidence made at the time by someone involved: a log, a letter, a customs record, an object.",{"term":860,"meaning":861,"example":862},"Range (statistics)","The difference between the highest and lowest value in a dataset; a quick measure of how spread out it is.","The 1492 population estimates have a range of over 100 million.",{"term":864,"meaning":865},"Evidence category","A label such as supports, contradicts, not relevant or uncertain, used to judge how a piece of evidence relates to a claim.",{"id":867,"type":868,"title":869,"questions":870},"quiz-investigate","quiz","Check what stuck",[871,884,897,910,923,936,949,961,974],{"itemId":872,"prompt":873,"options":874,"correct":148,"why":883},"exploration.investigate-q-columbus-belief","What is the real 'gap' between Columbus's stated reason and what actually happened?",[875,877,879,881],{"id":145,"label":876},"He never wanted to reach Asia in the first place",{"id":148,"label":878},"He aimed for Asia, was badly wrong about the distance, arrived elsewhere, and never accepted the mistake",{"id":151,"label":880},"He reached exactly where he intended",{"id":154,"label":882},"The gap is that his ships sank on the way home","His stated aim and his belief for the rest of his life stayed fixed on Asia, even though the actual landfall was thousands of kilometres short of it.",{"itemId":885,"prompt":886,"options":887,"correct":148,"why":896},"exploration.investigate-q-zheng-stop","Why did Zheng He's fleets stop after 1433, given that all seven voyages had reached their destinations safely?",[888,890,892,894],{"id":145,"label":889},"A storm destroyed every ship at once",{"id":148,"label":891},"The Ming court chose to spend money elsewhere and stopped funding new fleets",{"id":151,"label":893},"The navigators forgot how to find the route",{"id":154,"label":895},"Foreign rulers refused to let the fleets return","The stop was a decision made at court, not a failure at sea. The voyages themselves had worked every time.",{"itemId":898,"prompt":899,"options":900,"correct":148,"why":909},"exploration.investigate-q-monsoon-delay","If a monsoon that normally starts on time is instead delayed by several weeks, what is the main effect on a merchant fleet waiting to sail?",[901,903,905,907],{"id":145,"label":902},"Nothing changes; ships can leave whenever they like",{"id":148,"label":904},"The whole year's sailing and trading cycle is pushed back by roughly that delay",{"id":151,"label":906},"The ships must return home immediately",{"id":154,"label":908},"The delay only affects ships travelling in the opposite direction","Sailing ships depend on the wind being there, not on the calendar. A delayed monsoon pushes the whole cycle, including the return leg, later.",{"itemId":911,"prompt":912,"options":913,"correct":148,"why":922},"exploration.investigate-q-range","Why does the population-of-the-Americas dataset need its range checked, even though its mean and median look sensible?",[914,916,918,920],{"id":145,"label":915},"Because the mean and median were calculated incorrectly",{"id":148,"label":917},"Because a narrow-looking average can still sit in the middle of a genuinely wide disagreement between historians",{"id":151,"label":919},"Because ranges are always more accurate than averages",{"id":154,"label":921},"Because the numbers are all exactly the same","The mean and median can look tidy while the range shows that the underlying estimates disagree by a huge amount, which is the more important fact.",{"itemId":924,"prompt":925,"options":926,"correct":151,"why":935},"exploration.investigate-q-opened","The claim \"da Gama single-handedly opened Indian Ocean trade to the world\" survives evidence-sorting only if you change which word?",[927,929,931,933],{"id":145,"label":928},"\"Vasco\"",{"id":148,"label":930},"\"1498\"",{"id":151,"label":932},"\"Opened\", which should really be something closer to \"joined\"",{"id":154,"label":934},"\"Trade\"","Almost every piece of contradicting evidence attacks the idea that the ocean needed opening at all. What was genuinely new was a direct connection from Europe.",{"itemId":937,"prompt":938,"options":939,"correct":148,"why":948},"exploration.investigate-q-passage","Why does the passage about the Calicut gift-giving need to be read with 'whose viewpoint' in mind?",[940,942,944,946],{"id":145,"label":941},"Because it might contain spelling mistakes",{"id":148,"label":943},"Because it survives mainly through the visiting side's own accounts, with almost nothing recorded from the shore",{"id":151,"label":945},"Because it was written in a foreign language",{"id":154,"label":947},"Because the events did not really happen","One side's account surviving, and being repeated in books ever since, is not the same as it being the complete picture.",{"itemId":950,"prompt":951,"options":952,"correct":148,"why":960},"exploration.investigate-q-fleetsize","What does comparing Zheng He's fleet with Magellan's expedition show about fleet size and success?",[953,954,956,958],{"id":145,"label":704},{"id":148,"label":955},"Fleet size affects what a voyage can carry and how safely, but does not by itself decide whether it counts as a success",{"id":151,"label":957},"Fleet size has never mattered in the history of exploration",{"id":154,"label":959},"Only fleets that returned with every ship intact are remembered today","Zheng He's huge, safe fleet was stopped by a political decision; Magellan's small, badly reduced fleet still achieved the feat it is remembered for.",{"itemId":962,"prompt":963,"options":964,"correct":148,"why":973},"exploration.investigate-q-generalisation","How many solid counterexamples does it take to disprove a generalisation that uses the word 'every'?",[965,967,969,971],{"id":145,"label":966},"None; 'every' claims cannot be tested",{"id":148,"label":968},"Just one",{"id":151,"label":970},"At least half of all the cases",{"id":154,"label":972},"It depends on how famous the claim is","A claim that says 'every' or 'always' is broken by a single solid exception, which is what makes such claims expensive to state honestly.",{"itemId":975,"prompt":976,"options":977,"correct":148,"why":986},"exploration.investigate-q-hypothetical","What is the purpose of scaling Magellan's survival fraction onto the size of Zheng He's fleet?",[978,980,982,984],{"id":145,"label":979},"To claim that this actually happened to Zheng He's crews",{"id":148,"label":981},"To show, with real arithmetic, the scale of risk difference between the two voyages, as a constructed comparison",{"id":151,"label":983},"To prove that Zheng He's fleet was poorly organised",{"id":154,"label":985},"To calculate the exact number of ships Zheng He owned","The hypothetical never happened; it is a tool built from two real numbers to make a scale of difference easier to grasp.",{"id":988,"type":989,"title":990,"points":991},"summary-investigate","summary","The short version",[992,993,994,995,996,997,998],"**Compare stated reason with actual result.** Columbus aimed for Asia, missed by thousands of kilometres, and never admitted it. Zheng He's fleets did exactly what was asked, and were still stopped by a decision at court.","**A 'what if' tests understanding.** Only da Gama's route among four voyages depends on the monsoon; delaying that wind by weeks pushes back a whole year's trading cycle.","**One number can hide a real argument.** The nine published estimates for the 1492 Americas population range across 104 million even though the mean (55.8) and median (54) look tidy.","**Sort evidence before accepting a claim.** \"Da Gama opened Indian Ocean trade\" survives only as \"da Gama joined a new direct European link to an ocean already trading for a thousand years.\"","**One surviving account is one viewpoint.** The Calicut gift-giving is known mainly through the visiting side's own record; ask whose eyes any passage is written through.","**'Always' and 'every' need every case to agree.** Royal funding, being first, bigger fleets winning and reaching an intended destination all fail as universal claims once tested against real voyages.","**A hypothetical is a tool, not a fact.** Scaling Magellan's real survival fraction (about 6.7%) onto Zheng He's much larger fleet gives about 1,853 hypothetical survivors, showing scale without claiming it happened.",{"id":1000,"type":1001,"sourceIds":1002},"sources-investigate","sources",[1003,1004,1005,1006,1007,1008,1009],"exploration-britannica-vasco-da-gama","exploration-britannica-zheng-he","exploration-wiki-periplus","exploration-wiki-magellan","exploration-wiki-americas-population","exploration-britannica-cook","exploration-britannica-ibn-battuta",[1003,1004,1005,1006,1007,1008,1009],"needs_review",{"generatedBy":1013,"notes":1014},"claude-code","Draft generated locally; pending owner review. Reuses numbers.py's asserted values and adds one new computation in this file (scaling Magellan's survival fraction onto Zheng He's fleet size, with its own asserts). No new lat\u002Flon waypoints invented; voyage-map reuses voyages.py entries unchanged. The annotated passage is explicitly labelled a paraphrase, not a verbatim quotation.","803a97e836d8d8a5d7cec4544ea3ec7a46a1ad8a6c63de7ba2d44000679557ac",{"logic:practice":1017,"component:voyage-map@1":1018,"component:data-lab@1":1019,"component:evidence-sort@1":1020,"component:annotated-passage@1":1021,"component:sort-game@1":1022,"source:exploration-britannica-cook":1023,"source:exploration-britannica-ibn-battuta":1024,"source:exploration-britannica-vasco-da-gama":1025,"source:exploration-britannica-zheng-he":1026,"source:exploration-wiki-americas-population":1027,"source:exploration-wiki-magellan":1028,"source:exploration-wiki-periplus":1029},"3d6b0fe1b15255975a32b0fcd94e8019bc959ad45cbf12e136e86149549c6878","39a0c4da8ea3e6637b0b63d8c38cb151ee52e167eae571f75affe7452f56f13a","466896cc37735f48db03875fe9c9ce42fc8bcb7e5f937c9779d70513703b91bd","c7e7eaaef730a3b3d27bdd2d3ed613ea3fa67dbbb73b43f0def434174123b68e","01b198728ef96e7c1b785498b3191996743257c9617949f5d5a0fc94cbfacca1","b164f45a2c8ca08f26c450768ff0231e113e9fe45381eddb34dc6d0548596c38","785b5f408cbe9c49dfc60c0b77151f39125515f054399b45b9e335cc611adf4b","a13d35e0e7729889a1bcc756f6b9516a3814aae0d7a056ec8b9e8d489972b581","e054215ae428cfb850b8b8daf570a0985e9ba2947d2d76f0d749b0fcac1ee180","b637778770519d258063cb94693d79fc289531d021d4ba136468117af61e1dca","0b0e6f85230ee89d0d7dc39590470f0282baad1c9e65aa9e7b0a3c8dfd0c021c","f35819f113af55113ffe01fc8ea9e7bdda0703d09c24081ad9cf70dfffc99efa","dca5e18a4b6295658748ff81b58653f6e24948c3f4d174c3763e478396e53da5",{"state":1031,"reviewer":1032,"selfReview":339,"reviewedAt":1033,"method":1034},"approved","The library owner","2026-09-20T10:18:37.581Z","owner_bulk","preview-7e1cbbcc4f",1789899598731]