Unit 1: Thinking Geographically - Foundational Terms
Types of Diffusion (Expansion, Relocation, Hierarchical)
Diffusion describes the process by which a characteristic spreads across space from one place to another over time. Understanding the distinction between relocation diffusion and expansion diffusion is critical for identifying patterns in migration and cultural spread. Relocation diffusion occurs when the individuals who carry an idea or innovation physically move to a new location, such as the spread of the Spanish language to Central and South America via colonization. In contrast, expansion diffusion involves the spread of a feature from one place to another in an additive process. Within expansion, the exam frequently tests hierarchical diffusion, where an idea spreads from nodes of authority or power (like a fashion trend starting in Paris before hitting suburban malls), and contagious diffusion, which is the rapid, widespread diffusion of a characteristic throughout the population without regard for hierarchy, much like a viral video. Finally, stimulus diffusion occurs when the underlying principle spreads but the specific characteristic is rejected, such as the concept of a fast-food burger spreading to India but being adapted to a veggie option to respect local Hindu dietary restrictions.
Map Projections & Types of Distortion
No map can perfectly represent the three-dimensional Earth on a two-dimensional surface, leading to inevitable distortion in shape, distance, relative size, or direction. The Mercator projection is a classic exam example; while it preserves direction—making it invaluable for marine navigation—it severely exaggerates the size of landmasses near the poles, making Greenland appear as large as Africa. Conversely, the Peters projection focuses on equal area, representing the relative sizes of continents accurately but distorting their shapes. Geographers often use the Robinson projection as a compromise, distorting all four properties slightly to create a visually balanced map. On the AP exam, you must be able to identify which projection is being used in a stimulus and explain how its specific distortion might bias a viewer’s perception of global importance or spatial relationships. For instance, a Mercator map might lead to a Eurocentric worldview by shrinking equatorial regions where many Less Developed Countries (LDCs) are located.
Geospatial Technologies (GPS, GIS, Remote Sensing)
Modern geography relies on a suite of technological tools to gather and analyze spatial data. Remote sensing involves the acquisition of data about Earth's surface from a satellite orbiting the planet or from other long-distance methods. This technology is essential for monitoring environmental changes, such as urban sprawl or deforestation in the Amazon. The Global Positioning System (GPS) uses a constellation of satellites to determine the precise position of something on Earth, primarily used for navigation and field coding. The most complex of these is the Geographic Information System (GIS), a computer system that stores, organizes, analyzes, and displays geographic data in layers. GIS allows geographers to calculate relationships between different variables, such as overlaying soil types, rainfall patterns, and transportation networks to determine the best location for a new farm. On the exam, remember that GIS is about analysis and layering, while GPS is about location and navigation.
Unit 2 & 3: Population & Cultural Patterns
Demographic Transition Model Stages & Characteristics
The Demographic Transition Model (DTM) is a cornerstone of the curriculum, tracking how a country’s population structure changes as it develops economically. Stage 1 is characterized by high birth and death rates, resulting in low natural increase; no country is currently in Stage 1. Stage 2 features a plummeting death rate due to improvements in food supply and sanitation (the Second Agricultural Revolution), while birth rates remain high, leading to a population explosion. This is typical of many Sub-Saharan African nations today. Stage 3 sees birth rates begin to fall as societies urbanize and women gain access to education, slowing the Rate of Natural Increase (RNI). Stage 4 represents low birth and death rates, leading to Zero Population Growth (ZPG), common in the United States and much of Europe. Some geographers argue for a Stage 5, where birth rates fall below death rates, leading to a shrinking, aging population, as seen in Japan or Germany. You must link these stages to the Epidemiological Transition Model, which explains that Stage 2 is dominated by infectious diseases, while Stages 3 and 4 are dominated by degenerative diseases like heart disease or cancer.
Cultural Concepts (Folk vs. Popular Culture, Cultural Landscape)
Culture is divided into two primary categories based on scale and origin. Folk culture is traditionally practiced by small, homogeneous groups living in isolated rural areas. It changes slowly and is often deeply tied to the local environment, such as the specific building materials used in Amish housing. Popular culture is found in large, heterogeneous societies that share certain habits despite differences in other personal characteristics. It spreads rapidly through hierarchical diffusion and modern communications, often leading to a uniform landscape where different locations look identical (e.g., the presence of the same fast-food chains globally). The cultural landscape, a term coined by Carl Sauer, refers to the visible imprint of human activity and culture on the landscape. This includes everything from religious architecture (like minarets on a mosque) to the way fields are divided. On the exam, look for how popular culture can lead to cultural homogenization and the loss of local folk traditions.
Language Families, Religions, and Ethnicity Terms
Language and religion are the primary drivers of cultural identity and conflict. The largest language family is Indo-European, which includes English, Spanish, and Hindi. You should understand the hierarchy: Language Family > Branch > Group > Language > Dialect. For religion, the distinction between universalizing religions (Christianity, Islam, Buddhism) and ethnic religions (Hinduism, Judaism) is vital. Universalizing religions actively seek converts and have a wide global distribution, whereas ethnic religions are usually tied to a specific physical location and ethnic group. Use the term centripetal force to describe factors that unify a state (like a shared religion) and centrifugal force for those that divide it (like multiple competing ethnicities or languages). A classic exam scenario involves sequant occupance, where successful societies leave their cultural imprints on a place, each contributing to the cumulative cultural landscape over time.
Unit 4 & 5: Political & Agricultural Geography
Nation, State, Nation-State, Stateless Nation
Precise definitions are mandatory in political geography. A state is a formal political unit with a permanent population, defined boundaries, and sovereignty (control over its internal and external affairs). A nation is a group of people with a common culture and history who occupy a particular territory. A nation-state exists when the boundaries of the nation match the boundaries of the state, such as in Japan or Iceland. However, many groups are stateless nations, meaning they have a distinct cultural identity but no sovereign territory of their own; the Kurds in Southwest Asia are the most frequently cited example on the exam. Additionally, a multinational state contains more than one nation (e.g., the UK with Scots, Welsh, and English), while a multistate nation is a nation that stretches across borders, like the Koreans divided between North and South. Misusing these terms on an FRQ can lead to a significant loss of points.
Boundary Types (Geometric, Consequent, Superimposed)
Boundaries define the limits of state jurisdiction and are categorized by how they were created and what they follow. Geometric boundaries are straight lines drawn on a map, such as the 49th parallel between the U.S. and Canada. Consequent boundaries (or cultural boundaries) are drawn to accommodate existing religious, linguistic, or ethnic differences, such as the border between Pakistan and India. A superimposed boundary is one placed by an outside power with no regard for the existing cultural landscape; the borders created by European powers during the Berlin Conference in Africa are the primary example. These often lead to conflict as they split ethnic groups or force rival groups into the same state. You should also be familiar with relic boundaries, which no longer function but are still visible on the landscape, like the Berlin Wall, and antecedent boundaries, which existed before the cultural landscape emerged.
Von Thünen's Model & Agricultural Revolutions (First, Second, Green)
Von Thünen's Model explains the location of agricultural activities based on rent and transportation costs. In his concentric circles, dairying and intensive farming occur closest to the city because products are perishable and expensive to transport. Moving outward, you find forests (for fuel), then extensive field crops (like wheat), and finally ranching in the outermost ring where land is cheapest. Agriculture has evolved through three major phases. The First Agricultural Revolution was the initial transition from hunting and gathering to sedentary farming (the Neolithic Revolution). The Second Agricultural Revolution coincided with the Industrial Revolution, introducing mechanization and the enclosure movement, which increased yields and pushed displaced peasants into factory jobs. The Green Revolution (the Third Agricultural Revolution) in the mid-20th century introduced high-yield seeds and chemical fertilizers to LDCs, drastically increasing food production in places like India but also creating environmental concerns regarding pesticide use and groundwater depletion.
Unit 6 & 7: Urban & Economic Geography
Urban Models (Concentric Zone, Sector, Multiple Nuclei, Galactic)
Urban models describe the internal structure of cities. The Burgess Concentric Zone Model suggests a city grows outward from a central business district (CBD) in a series of rings, with the poorest residents living in the inner transition zone and the wealthiest in the commuter zone. The Hoyt Sector Model argues that cities develop in wedges or sectors, often following transportation corridors like rail lines or highways. The Multiple Nuclei Model by Harris and Ullman suggests that a city is a complex structure with more than one center around which activities revolve (e.g., a university or airport acting as a secondary node). Finally, the Galactic City (Peripheral) Model reflects the modern North American city, where a decentralized CBD is surrounded by "edge cities" connected by a beltway or ring road. Understanding these models allows you to analyze gentrification—the process of middle-class people moving into deteriorated inner-city neighborhoods and renovating them—and its impact on lower-income residents.
Rostow's Stages of Growth & Wallerstein's World Systems Theory
Economic development is often viewed through two competing lenses. Rostow's Stages of Economic Growth is a modernization model suggesting all countries follow a five-stage linear path: Traditional Society, Preconditions for Takeoff, Takeoff (industrialization), Drive to Maturity, and High Mass Consumption. This model assumes that with investment and trade, any LDC can reach the level of a More Developed Country (MDC). In contrast, Wallerstein's World Systems Theory is a structuralist model that views the global economy as a fixed hierarchy. It divides the world into the Core (MDCs with high tech and wealth), the Periphery (LDCs providing raw materials and cheap labor), and the Semi-Periphery (countries like Brazil or China that have qualities of both). Wallerstein argues that the Core exploits the Periphery, making it difficult for poorer nations to advance. On the exam, you may be asked to compare these models to explain the persistent "development gap" between the Global North and Global South.
Agglomeration, Bulk-Reducing/Gaining Industries, GDP vs. GNI
Industrial location is often determined by the cost of transporting raw materials versus finished products. A bulk-reducing industry is one where the final product weighs less than the inputs (e.g., copper smelting or paper milling); these factories locate near the raw materials to save on shipping. A bulk-gaining industry is one where the product gains weight or volume during production (e.g., soft drink bottling or car assembly); these locate near the market. Agglomeration refers to the clustering of similar or related industries in one area to share specialized labor and infrastructure, such as high-tech firms in Silicon Valley. To measure the success of these economies, geographers use Gross Domestic Product (GDP), the value of goods and services produced within a country, and Gross National Income (GNI), which includes money that leaves and enters the country via international investment. These metrics help identify the Human Development Index (HDI), which combines income, literacy, and life expectancy to rank a country’s overall development.
Unit 8: Industrial & Economic Development
Measures of Development (HDI, GII, IMR, Literacy Rate)
Development is a multifaceted concept that goes beyond simple wealth. The Human Development Index (HDI) is the gold standard for assessment, but geographers also look at the Gender Inequality Index (GII) to determine how much potential is lost due to disparities between men and women in reproductive health, empowerment, and labor market participation. Lower GII scores indicate higher levels of equality and are usually correlated with higher HDI. Demographic indicators like the Infant Mortality Rate (IMR)—the number of deaths of infants under one year old per 1,000 live births—and the Literacy Rate provide insight into the quality of a country's healthcare and education systems. When analyzing these statistics on the exam, remember that a high GNI doesn't always guarantee high social development; you must look at how wealth is distributed and invested in the population’s well-being.
Sustainable Development & UN Sustainable Development Goals (SDGs)
As industrialization continues, the focus has shifted toward sustainable development, which meets the needs of the present without compromising the ability of future generations to meet theirs. The United Nations established 17 Sustainable Development Goals (SDGs) to be achieved by 2030, targeting issues like poverty, hunger, gender equality, and climate change. A key concept here is the ecumene, the portion of Earth's surface occupied by permanent human settlement. As the ecumene expands, the pressure on natural resources increases. You should be able to discuss how countries balance industrial growth with environmental protection, often through the use of renewable energy sources or the implementation of "green" building codes in urban planning. The exam frequently asks about the trade-offs involved in these decisions, particularly for LDCs that may feel that environmental regulations hinder their path to economic takeoff.
Microloans, Ecotourism, and Fair Trade as Development Strategies
To bridge the development gap, several alternative strategies have emerged. Microloans (or microfinance) involve providing small, low-interest loans to individuals in LDCs, particularly women, to start small businesses. Programs like the Grameen Bank have shown that these small investments can significantly reduce local poverty and empower marginalized groups. Ecotourism is another strategy where countries utilize their natural beauty to attract tourists in an environmentally responsible way, providing income while incentivizing the preservation of ecosystems (e.g., Costa Rica’s rainforests). Finally, fair trade is a movement that ensures producers in LDCs receive a fair price for their goods, such as coffee or cocoa, by bypassing some of the exploitative middle-men in the global supply chain. These strategies represent a shift away from top-down, large-scale industrial projects toward more localized, sustainable economic models that directly benefit the "bottom of the pyramid."
Applying Your Cram Sheet in Practice Questions
Using Terms to Decode Multiple-Choice Stems
The multiple-choice section of the AP exam often uses complex phrasing to test your understanding of simple concepts. When you encounter a question about a "spatial distribution pattern," your brain should immediately look for terms like clustered, dispersed, or linear. If a question mentions "distance decay," it is asking about the friction of distance—the idea that the farther away two groups are, the less likely they are to interact. By scanning the question stem for essential APHG definitions, you can quickly eliminate distractors. For example, if a question asks about the "site" of a city, any answer choice describing its "situation" (like its proximity to a railroad) is automatically incorrect. Use this APHG vocabulary list as a mental filter to strip away the fluff from the core geographic problem being presented.
Incorporating Models into FRQ Responses for Maximum Points
On the FRQ portion of the exam, you are often required to "describe," "explain," or "compare." To earn the highest marks, you should explicitly name and apply the APHG models and theories cheat sheet concepts. Don't just say a city is growing; say it is exhibiting patterns consistent with the Galactic City Model due to the development of edge cities along suburban beltways. If you are discussing a country’s population, don't just say the birth rate is falling; explain that the country is transitioning into Stage 3 of the Demographic Transition Model as it urbanizes. Providing this level of theoretical backing demonstrates to the graders that you aren't just guessing based on general knowledge, but are applying the specific tools of a geographer. Always define your terms before applying them to the specific case study or data set provided in the prompt.
Quick-Reference During Final Review Sessions
In the final days before the exam, use this last minute AP Human Geography review to conduct active recall sessions. Instead of just reading the terms, cover the definitions and try to explain the concept to someone else—or even to yourself out loud. Can you draw the Von Thünen rings from memory? Can you list the three types of expansion diffusion? If you find a gap in your knowledge, such as the difference between acculturation (adopting some traits of a host culture) and assimilation (losing original cultural traits entirely), focus your remaining study time there. This targeted approach ensures that you are not wasting time on concepts you already master, allowing you to refine your understanding of the most complex geographic concepts to know for exam day. Success is built on the precision of your vocabulary and the depth of your conceptual links.