Chapter 2. Understanding Data

Populations, Processes, and Samples 20

Representativeness and Sampling 21

Simple Random Sampling 21

Stratification, Clustering, and Complex Sampling 23

Non-Random Sampling 26

Cross-Sectional and Time Series Sampling 27

Study Design: Experimentation, Observation, Surveying 27

Experimental Data—An Example 28

Observational Data—An Example 31

Survey Data—An Example 31

Loading Data into a Data Table 34

Entering Data from the Keyboard 34

Moving Data from Excel Files into a JMP Data Table 38

Application 39