The Effects of Class Interval Systems on Choropleth Map Correlation
Bibliographic Data
| ID | 14701383 |
|---|---|
| Authors | Judy M Olson (corresponding author), Judy Olson (University of Georgia) |
| Year | 1972 |
| Volume | 9 |
| Issue | 1 |
| Pages | 44-49 |
| Publication date | 1972-06-01 |
| Peer Reviewed | Yes |
| Open Access | No |
| Type | ARTICLE |
| Venue | Cartographica The International Journal for Geographic Information and Geovisualization (JOURNAL) |
| Journal identifiers | ISSN: 0317-7173 • E-ISSN: 1911-9925 |
| Publisher | University of Toronto Press Inc. (UTPress) (PUBLISHER) |
| DOI | 10.3138/k775-4923-8185-0341 |
| OpenAlex | W1989196684 |
| Language | EN |
| Citations received | 3 |
The correlation between a pair of distributions is often measured with the product-moment correlation coefficient, r. But the choropleth maps of the same distributions may be more alike or less alike than that coefficient would indicate. The degree to which map likeness corresponds to the correlation between the data before mapping is affected by the class interval method used. Using rank correlation (Kendall's t) to measure the map correlation and drawing data from normal distributions, it is found that: (1) there is a mathematically expressible curvilinear relationship between the product-moment correlation and the expected map correlation; (2) this relationship appears to remain identical regardless of class interval system; (3) the standard deviation about the expected values does vary from one class interval system to another. Smaller standard deviations are associated with increased numbers of observations within each variable and with increased numbers of intervals. For a given r value, number of observations, and number of intervals, systems with more nearly equal numbers of observations in each category have smaller standard deviations
Class (philosophy · Combinatorics · Correlation · Correlation coefficient · Degree (music · Fisher transformation · Geometry · Interval (graph theory · Measure (data warehouse · Moment (physics · Physics · Rank correlation · Standard deviation · Statistics · Advanced Statistical Methods and Models · Mathematics
| Unique citing works | 3 |
|---|---|
| Citations per year | 0,06 |
| Citation span | 1977 - 2025 (49) |
| Citation velocity | recent |
| Highly cited | No |
| Citation types | Neutral: 2 |