2 Data and Measurement We begin with a discussion of the nature of data, and discuss the importance of understanding data in its context. We differentiate quantitative from categorical data and define the concept of a variable. Students collect some data on themselves and take a first look at it in Data Desk. Key Points Data systematically recorded information, whether numbers or labels, together with a context. Variables hold the same information about many inPiduals.
Cases holds all the information for a single inPidual.
Quantitative data numeric data in which the numbers are measurements. Units a quantity or amount adopted as a standard of measurement, such as dollars, hours, or grams. Class discussion here can fill in the W's and identify quantitative and categorical variables. Students see quickly that the real world isn't all that simple. The class data can be put into a Data Desk file and returned to the class for homework exercises or used in analyses to illustrate subsequent classes.