Thematic Mapping Techniques Questions and Answers

Answer: C

Correct answer: shows variation within each areal unit

A choropleth fills the whole unit with one tone, implying a uniformity that rarely exists. A dot map places dots where the phenomenon actually is, so an empty half of a district appears empty and a crowded corner appears crowded - and clusters that straddle boundaries become visible. Dot maps do also work directly from counts, but that is a difference in data requirement rather than the advantage the technique exists for.

Answer: D

Nine hundred out of nine thousand is 10 per cent, which lies in the 8 to 12 band, the third class. Converting the count to the mapped rate before consulting the legend is the step most often skipped, and reading the raw count against the classes would put the district in the wrong band.

Answer: A

The first shows where facilities are concentrated, the second where provision is adequate relative to need. A large city may lead on the first measure and trail badly on the second, so the two maps support different conclusions.

Answer: B

Correct answer: in a lighter weight than the theme

The base map is there to let the reader locate the theme, not to compete with it, so it is drawn in lighter weights and muted tones and stripped of anything the theme does not need. Getting this wrong is a common fault: a full-strength topographic base beneath a thematic layer leaves the reader hunting for the subject among the coastlines and roads.

Answer: C

Both are true and the reason explains why: one extra case in a district of two hundred people moves the rate sharply, so a striking tone may rest on almost no evidence. Reporting the counts lets the reader discount such units.