After reading this chapter, you should be able to:
1 Describe two criteria that make variables suitable for scientific investigation.
2 Delineate the need for constructs and operational definitions in research.
3 Distinguish between continuous and discrete variables, and between quantitative and qualitative variables.
4 State the four scales of measurement, and provide an example for each.
5 Describe the following types of reliability: test-retest reliability, internal consistency, and interrater reliability.
6 Describe the following types of validity: face validity, construct validity, criterion-related validity, and content validity.
7 Identify the concerns of participant reactivity, experimenter bias, and sensitivity and range effects for selecting a measurement procedure.
8 Explain why the failure to replicate a result is not sufficient evidence for fraud.
9 Enter data into SPSS by placing each group in a separate column and each group in a single row (coding is required).