Goode's Homolosine is an interrupted, equal-area map projection that preserves the true size of land masses by slicing the globe apart (mostly through the oceans), sacrificing continent shapes and ocean continuity. In AP Human Geography, it's the go-to example of trading shape distortion for accurate area.
Goode's Homolosine projection looks like someone peeled an orange and flattened the skin. That weird, interrupted shape is the whole point. By cutting the map apart (mostly through the oceans), the projection keeps the area of continents and countries accurate. Greenland looks its actual size instead of being inflated to the size of Africa. The trade-off is that shapes get stretched near the cuts, and you can't trace a continuous route across an ocean because the oceans are sliced up.
This matters because of a core idea in the CED (EK IMP-1.A.3): every map projection distorts something, whether it's shape, area, distance, or direction. No flat map gets all four right. Goode's Homolosine chooses area as the thing to protect, which makes it ideal for thematic maps showing global data like population density, climate zones, or land use, where comparing the size of regions actually matters.
Goode's Homolosine lives in Topic 1.1 (Introduction to Maps and Types of Maps) in Unit 1: Thinking Geographically, supporting learning objective 1.1.A. The CED's essential knowledge is blunt about it: all maps are selective, and projections inevitably distort spatial relationships in shape, area, distance, and direction. The exam wants you to do more than name projections. You need to explain what each one distorts, what it preserves, and why a cartographer would pick it for a particular purpose. Goode's is your cleanest example of a projection built around one priority (true area), and it pairs perfectly with Mercator as the opposite trade-off. Unit 1 skills like this come back all year, because every thematic map you analyze in Units 2-7 was built on someone's projection choice.
Keep studying AP Human Geography Unit 1
Equal-area projection (Unit 1)
Goode's Homolosine is the most famous member of this family. Equal-area projections keep land sizes proportional to reality, which is exactly what you want when a map's job is comparing regions, like showing where most of the world's population lives.
Mercator Projection (Unit 1)
Mercator is Goode's mirror image. Mercator preserves shape and direction (great for navigation) but massively inflates areas near the poles, while Goode's preserves area but mangles shapes and chops up the oceans. Exam questions love asking you to match the projection to the purpose.
Distortion (Unit 1)
Goode's is a walking proof of EK IMP-1.A.3, the rule that no flat map escapes distortion. The interruptions are literally the distortion made visible. The cartographer cut the map apart rather than let area errors creep in.
Dot Distribution Map (Unit 1)
Thematic maps like dot distribution maps often sit on top of an equal-area projection like Goode's. If the base map inflated land areas, the dots would look misleadingly dense or sparse, so projection choice quietly shapes how you read the data.
Goode's Homolosine shows up in Unit 1 multiple-choice questions about map projections and distortion. A typical stem shows you the projection (or describes a map with 'interruptions') and asks what it preserves, what it sacrifices, or why a geographer would choose it for displaying global data. The move you need to make is matching projection to purpose, so Goode's equals accurate area, good for thematic world data, bad for navigation. No released FRQ has asked about this projection by name, but FRQs frequently hand you a thematic map as a stimulus, and recognizing the projection's built-in trade-offs sharpens how you interpret it. The one fact to lock in is that every projection distorts at least one of shape, area, distance, or direction, and Goode's chose to protect area.
These two are opposite answers to the same problem. Mercator is a rectangular, conformal projection that keeps shapes and compass directions accurate, which made it perfect for sailing, but it blows up areas near the poles (the classic giant-Greenland problem). Goode's Homolosine does the reverse. It keeps areas true by interrupting the map, so sizes are honest but shapes warp and oceans get split. If a question asks which projection to use for comparing the size of regions or showing global data, pick Goode's. If it asks about navigation or constant compass bearings, pick Mercator.
Goode's Homolosine is an interrupted, equal-area projection, meaning it keeps land sizes accurate by cutting the map apart, mostly through the oceans.
Its trade-off is shape and continuity. Continents look distorted near the cuts, and you can't follow a continuous route across an ocean.
It's the preferred base for thematic maps of global data (population density, climate, land use) because comparing region sizes only works if those sizes are true.
Goode's and Mercator are opposites. Mercator preserves shape and direction but distorts area, while Goode's preserves area but distorts shape.
It directly illustrates EK IMP-1.A.3: every map projection inevitably distorts shape, area, distance, or direction, so cartographers choose what to sacrifice based on the map's purpose.
It's an interrupted, equal-area map projection that keeps the size of continents and countries accurate by slicing the globe apart, usually through the oceans. It's the standard AP example of a projection that sacrifices shape to preserve area.
It's accurate for area, but not for everything. It shows the true relative size of land masses, but shapes are distorted near the interruptions and the oceans are cut up, so distances and routes across water are unusable. No flat map is accurate in all four properties (shape, area, distance, direction).
Mercator preserves shape and direction but wildly inflates areas near the poles, making Greenland look as big as Africa. Goode's does the opposite, keeping areas true while distorting shapes and interrupting the oceans. Mercator suits navigation; Goode's suits global thematic data.
The interruptions are how the projection avoids area distortion. Instead of stretching land to fill a rectangle, it 'peels' the globe like an orange and lets the gaps fall in the oceans, so continents keep their true sizes.
When the map's purpose is comparing global data across regions, like population density, climate patterns, or agricultural land use. Since it's equal-area, the visual size of each region honestly reflects its real size, which keeps thematic data from being misleading.
Connect this key term to the AP exam workflow: review the course, practice questions, and check related study tools.
Review units, study guides, and course resources.
Check this vocabulary in multiple-choice context.
Apply key concepts in written AP responses.
Estimate the exam score you are working toward.
Review the highest-yield facts before practice.
Put the full course together before test day.