Читать книгу Interpreting and Using Statistics in Psychological Research - Andrew N. Christopher - Страница 41

1 How might we operationally define each of the following constructs? Realize that for each construct, there are many possible ways to operationalize it, more than I’ve provided in the answers.HostilityA: blood pressure while interacting with another person; self-report measure of the tendency to experience hostility toward othersHelping behaviorA: number of times people hold the door open to a building for other people over a period of time; number of hours a person volunteers in his or her community each weekIntelligenceA: Grade-point average (GPA); scores on a standardized test such as the Weschsler Adult Intelligence Scale (WAIS)Investment returnsA: interest earned on a savings account this past year; stock market gains or losses in the past yearExercise behaviorA: number of miles walked each day; number of pull-ups a person does each weekDietA: daily sodium intake; number of servings of fruits and vegetables each dayStressA: cortisol levels; blood pressureJob burnoutA: number of cynical comments a person makes at work each day; scores on a self-report measure of burnout (e.g., Maslach & Jackson, 1981)

2 In Terrell et al.’s (2008) research, how was the dependent variable operationally defined?A: The dependent variable of aggression was operationalized as the number of noise blasts delivered during the 10-minute experimental task.

3 In Terrell et al.’s (2008) research, how was the variable of “status of the other participant” operationally defined?A: It was operationalized with the answers to the six questions that appear in Table 2.1.

4 What is the difference between the reliability and the validity of a measurement?A: Reliability refers to consistency of the measurement, whereas validity refers to the appropriateness of the measurement.

5 Explain why a measurement can be reliable but not valid.A: We can consistently measure a variable (e.g., an adult person’s height) that is irrelevant to a given situation (e.g., parenting ability). An adult’s height won’t change much, if at all, so it is reliable. But I doubt physical height has anything to do with one’s effectiveness as a parent, so it is not valid.

6 Explain why a measurement cannot be valid if it is not also reliable.A: If a measurement is not providing consistent (reliable) scores, then we have no way of knowing what it is measuring (if it is valid). For instance, if we have a measure that is supposed to assess academic ability, but people don’t score reliably on it, then we cannot conclude it measures academic ability or anything else.