From the Help Desk - Legend Classification Methods
Hello readers! This week we provide an in-depth response to a question asking about the legend classification methods in SimplyAnalytics. This response is now part of our Help Center: https://simplyanalytics.zendesk.com/hc/en-us
Question: Can you explain the legend classification methods?
The classification method controls how the data in your map is grouped. Areas on the map are assigned to groups using different classification methods. The colors you see on the map depend on which class is assigned to each area.
There are multiple methods for calculating break points for the data. You can select any of the following from the Classification Method menu:
- Quantiles (Local)
- Quantiles (National)
- Natural Breaks (Local)
- Natural Breaks (National)
- Equal Intervals
- Custom
Quantiles (National): This is the default method used to classify each area on the map, and works for most situations. Breakpoints are calculated so that each category contains about the same number of features. "National" uses a sample of locations from throughout the USA to calculate the breakpoints.
Example: If there are 35,000 ZIP Codes nationally and you have 5 categories the legend is calculated so there are theoretically 7,000 ZIPs in each category.
Quantile classes are easiest to understand, but they can be misleading if the data being mapped is not distributed normally. For example, population counts are usually not suitable for quantile classification because only a few places are highly populated. Use population density or percentages for more meaningful maps.
Quantiles (Local): Breakpoints are calculated so that each category contains about the same number of features. "Local" uses a sample of locations from your current view to calculate the breakpoints. This method usually ensures the map will show more colors. For example, if there are 50 ZIP codes visible on your map, and you choose to display them in five classes, the map will show 10 ZIP codes per color.
Natural Breaks (National): Breakpoints are calculated using a statistical formula that finds groupings and patterns in the data. "National" uses a sample of locations from throughout the USA to calculate the breakpoints.
Natural Breaks (Local): Breakpoints are calculated using a statistical formula that finds groupings and patterns in the data. "Local" uses a sample of locations from your current view to calculate the breakpoints.
Equal Intervals: This method uses equal-size intervals for each class and color on the map. Breakpoints are calculated so that each category has the same range. This method doesn't care if all areas on the map end up sharing the same color.
Example: if the lowest value nationwide is 1 and the highest value is 100 for that specific geography the legend will have 5 equal categories 1 to 20, 21 - 40, 41 - 60, 61 to 80 and 81 to 100
Custom: The user selects their own breakpoints by typing in their own values.To set your own custom breakpoints, you can click in each value’s cell and enter a value of your choice. You can also click the colors to customize how the map looks.
More information on data classification/reference:
https://gisgeography.com/choropleth-maps-data-classification/
More from SimplyAnalytics
Posted on Feb 26, 2014 by Admin
The Statewide California Electronic Library Consortium is holding another packed week of workshops and networking during the SCELCapalooza event in March 2014. Geographic Research will b...
Posted on Apr 18, 2008 by Admin
A team of librarians at Drexel University has developed a detailed poster to introduce SimplyMap as a new research tool for the student body. The poster was launched on Drexel Research Da...
Posted on May 26, 2020 by Admin
Hello readers! We hope you are doing well, and thank you for your continued support of SimplyAnalytics. We are excited to announce that scatterplots are officially live! Scatter plots ar...
Posted on Jan 08, 2018 by Admin
The SimplyAnalytics team will be exhibiting at ALA Midwinter in Denver February 9-12. Stop by booth 2152 for a visit and a tour of SimplyAnalytics, the best-in-class analytics and data vi...
Posted on Nov 28, 2023 by Admin
Hello readers! We are happy to announce that SimplyAnalytics has successfully migrated to the Census 2020 boundaries on Sunday, November 19th. This blog will talk about what that is, what...
Posted on Sep 10, 2010 by Admin
SimplyMap Canada is now available at several Canadian institutions, including York University and Ryerson University, in Toronto. SimplyMap Canada has all of the great features included i...
Posted on Jun 08, 2015 by Admin
In this week’s report we take a look at one folder found within SimplyMap’s SimmonsLOCAL data package. SimmonsLOCAL is a powerful targeting and profiling system that provides insights int...
Posted on Jul 30, 2018 by Admin
Hello readers! Welcome to this week’s blog. This week we will feature the Related Data Table view and how you can use it to maximize your productivity in SimplyAnalytics. What is it? The ...
Posted on Oct 22, 2008 by Admin
Excerpt from University of Iowa Library blog: In your marketing class, you may be developing a marketing plan for a pre-made meals restaurant specializing in vegetarian menus in Chicagola...
Posted on May 16, 2022 by Admin
Hello readers! We hope you are having a wonderful day. Today we feature a question from the help desk that we think many users would find useful. Let’s get started. The question: How can ...
