Study Questions

Short Answer

1. Why do sampling errors exist in most psychological research studies?
Ans: In most cases, researchers collect data from samples of the target population, and there will always be differences between samples and populations. These differences result in sampling errors.
Learning Objective: 2-1: What is the difference between a population and a sample?
Cognitive Domain: Comprehension
Answer Location: Populations and Samples

2. A researcher is interested in overall physical health. Give an example of nominal scale, ordinal scale, interval scale, and ratio scale measures for this variable.
Ans: The answers may vary, but possible answer for nominal scale is asking the participants whether they are healthy or sick. The ordinal measure is asking them to rate themselves on “not at all healthy,” “somewhat healthy,” and “extremely healthy.” The interval measure could be asking people to rate their health on a 10-point scale. The ratio measure could be asking people to report how many sick days they’ve had in the last 12 months.
Learning Objective: 2-2: What kinds of data are collected in psychological studies?
Cognitive Domain: Application
Answer Location: Scales of Measurement

3. What does it mean to say that the distribution represents a negative skew?
Ans: Negative skew means that most of the scores are on the high end of the scale and very few scores are on the low end of the scale.
Learning Objective: 2-3: What is a distribution and how does its shape affect our analysis of the data
Cognitive Domain: Comprehension
Answer Location: Shape of a Distribution