AP Human Geography
Manipulating data can distort the desired results on a thematic map. A- Define what a choropleth, dot, and symbolic map is and how they measure intensity B- Discuss how each map can distort a map when you manipulate data for each. C- Discuss how a choropleth map can give false impressions when using a smaller (distance) scale versus a larger (distance) scale D- Discuss how changing the natural breaks to quintiles can give false impressions on a choropleth map. Thematic Map- A type of map that displays one or more variables-such as population, or income level-within a specific area. A- A choropleth map is a thematic map that uses tones or colors to represent spatial data as average values per unit data. Dot maps are thematic maps that use points to show the precise locations of specific observations or occurrences, such as crimes, car accidents, or births. A symbolic map is a thematic map where the symbol (circle, square, pumpkin, etc.) indicates the magnitude of some statistical value for a given geographic region.
B- In any type of thematic map, percentages can be used that distort data. Saying 10,000 out of 100,000 people have lung cancer in heavily populated areas sounds a lot worse that saying 10% or 1 out of 10 people have cancer in heavily populated areas. c- When a choropleth map uses a smaller scale, there is less variety of tones to represent data. For example; Presidential election maps have two colors, red and blue. this means that even if a state is only 1% over half for democratic, and 49% of that state voted for the republican party, the whole state is classified as democratic.
D- Natural breaks are based on the natural groups formed in a map, and only include the data that was given (skips numbers without data attached). Quintiles group the map into five sections of 20% each. changing natural breaks to quintiles can give false impressions on a choropleth map by manipulating the data from a natural equal position, to a