Lab 2 key (scored out of 50)
Part I.
1. Print screen of map from extra challenge on p. 469.
(out of 9)
--Dot density screenshot
2. What is the dimensionality of each of the data layers?
(out of 3)
Polygons/Two-dimensional.
Explanation: For both the dot density and choropleth maps, the geographic data is defined in terms of bounded areas (polygons). The attribute table makes this clear because it has a data row (an entry) for each area/polygon on the map. Data is calculated in terms of these polygons and visualized as dots or colors as per that area/polygon. Dots are randomly placed within the polygon and therefore are not point data.
FYI- Textbook’s Glossary definition: “dimensionality: The property of geographic features by which they are capable of being broken down into elements made up of points, lines and areas. This corresponds to features being zero-, one-, and two-dimensional.”
3. Print screen of resulting bx_demog layer resulting at end of task 4, p. 480.
Justify the number of classes that you use and the breaks in the data.
(out of 12)
--Choropleth screenshot
--Rational explanation of how the data is classified: natural breaks, equal interval, equal value, standard deviation etc…
Design tip: try not to use more than 6 classes. Humans often have trouble distinguishing more than that many classes.
4. What measurement levels of data are mapped?
(out of 3)
Nominal- minority race/ethnicity is a subjective category with without quantitative degrees of difference and to which the concept of “zero” is meaningless.
Measurement levels are a characteristic of the underlying data- they do not change with how it is visualized.
FYI- Textbook’s Glossary definition: “level of measurement: the degree of subjectivity associated with a measurement. Measurements can be nominal, ordinal, interval or ratio”
5. What are the two types of thematic maps covered in these exercises? What
questions are they best to describe?(out of 8)
Dot Density: Absolute, total numbers of things or people
Choropleth: Rates or averages over given areas
Part II.
1. Create informative layout of the data that you have worked with over the past 2
weeks. Include legends, titles, north arrow, scale, text, and bar chart. Text should
describe 1) name, section, and date , 2) data sources, and 3) describe the maps that
are displayed. Include dot density and chorpleth maps. Bar chart should be
properly labeled with title, legend, and use one option from your choices. The
final layout will be judged according to visual structure of the layout as described
in lab.(out of 15)
Image Checklist:
-geographic image
-title
-legend
-scale
-north arrow
-text
-bar chart—lab is problematic on this point
-visual hierarchies- composition/color etc…
-legibility