Statistics in a Nutshell

Chapter 19. Educational and Psychological Statistics

Many statistical techniques used in education and psychology are common to other fields of endeavor: these include the t-test (covered in Chapter 8), various regression and ANOVA models (covered in Chapters 12–15) and the chi-square test (covered in Chapter 10). The discussion of measurement in Chapter 1 will also prove useful since much of educational and psychological research involves constructs that cannot be observed directly and have no obvious units of measurement. Examples of such constructs include mechanical aptitude, self-efficacy, and resistance to change. This chapter concentrates on statistical procedures used in the field of psychometrics, which is concerned with the creation, validation, and use of tests and measurements applied to human intelligence, knowledge, abilities, and psychological characteristics such as personality traits.

The first question you may ask with regard to the use of statistics in education and psychology is why they are necessary at all. After all, isn’t every person an individual, and isn’t the point of education and psychology to perceive that person in all their individual richness, not to reduce them to a set of numbers or place them in comparison with others who may not really be comparable at all?

This is a valid concern and underscores what anyone working in the human sciences knows already: doing research on human beings is in many ways much more difficult than doing research in the ...