| Popis: |
Measurement is at the heart of all psychological testing and assessment. A number of statistical tests and procedures can be used to help evaluate how well a test measures what it is supposed to measure. The information presented in this chapter provides a solid foundation of basic statistical methods and concepts used in measurement. Rules for assigning numbers to represent objects and concepts are presented, involving four types of scales: nominal, ordinal, interval, and ratio. This chapter also describes how numbers are used to represent scores from individuals or groups of people, forming a distribution of scores. Various descriptive statistics are presented, such as measures of central tendency and measures of variability. Correlation coefficients are discussed in depth, along with an introduction to linear regression. |
