All quantitative variables are simple ones that could be counted

Explanation

The context of data includes an understanding of the variables that are recorded. Often the variables in a statistical study are easy to understand: height in centimetres, study time in minutes, and so on. But each area of work also has its own special variables. A psychologist uses the Minnesota Multiphasic Personality Inventory (MMPI), and a physical fitness expert measures “VO2 max,” the volume of oxygen consumed per minute while exercising at your instrument maximum capacity. Both of these variables are measured with special instruments. VO2 max is measured by exercising while breathing into a mouthpiece connected to an apparatus that measures oxygen consumed. Scores on the MMPI are based on a long questionnaire, which is also an instrument. Part of mastering your field of work is learning what variables are important and how they are best measured. Because details of particular measurements usually require knowledge of the particular field of study, we will say little about them.