Variable Types
| Site: | Clare-Gladwin RESD |
| Course: | Michigan Algebra II KHauck |
| Book: | Variable Types |
| Printed by: | Guest user |
| Date: | Sunday, May 19, 2024, 7:21 PM |
Description
Variable Types
Variable Types
When interpreting data and using data displays, it is essential to understand the types of variables involved. All variables come in one of two forms: quantitative or categorical. A quantitative variable is a variable that can be measured as a number. Some examples are height, age, crop yield, GPA, salary, and temperature. Any variable that is not quantitative is categorical. Categorical variables are variables with no natural sense of ordering. Some examples are hair color, gender, field of study, college attended, and political affiliation. Each of these examples has no numerical value.Data is more easily manipulated in an analysis spreadsheet when it's coded quantitatively; categorical variables are often disguised as quantitative variables. For example, one might record gender information coded as 0 = Male, 1 = Female. However, the variable is still categorical; it is not naturally measured as a number.
Continuous or Discrete
A continuous variable is one for which, within the limits of the variable's range, any value is possible. For example, the variable, "time to solve a math problem" is continuous since it could take 2 minutes, 2.13 minutes, etc., to finish the problem. The variable, "number of correct answers on a multiple choice test" is not continuous since it is not possible to get 54.12 problems correct. Other examples of continuous quantitative variables are temperature, age, height, weight and time. A variable that is not continuous is called discrete.A discrete quantitative variable is one that cannot take on all values within the limits of the range. For example, responses to a five point rating scale can only take on the values 1, 2, 3, 4, or 5. The variable cannot have the value 1.7. With a discrete variable it is possible to list all possible values. Other examples of discrete quantitative variables are the number of legs on an animal, number of siblings, ACT scores, IQ scores, and shoe size.
Interactive Activity
Practice
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Answer Key
Answer Key for Variable Types Worksheet
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Sources
Sources used in this book:Annenberg Media, "Glossary." http://www.learner.org/courses/learningmath/data/keyterms.html (accessed 07/27/2010).
Embracing Mathematics, Assessment & Technology in High Schools; a Michigan Mathematics & Science Partnership Grant Project
Lane, David M. "HyperStat: Continuous Variable." http://davidmlane.com/hyperstat/A96915.html (accessed 7/27/2010).
Wilson, James. "Intermath: Types of Data." http://intermath.coe.uga.edu/dictnary/descript.asp?termid=102 (accessed 7/26/2010).