Psych 2030 Textbook 2

In research, what is a population?

• The entire group a researcher wants to generalize to

• The subset of people actually studied

• Any group found in the lab

• The sample of participants who complete the survey

What is a sample in psychological research?

• The entire group a researcher hopes to understand

• A subgroup of the population actually studied

• A random set of variables

• A case study of one participant

Why is random sampling important?

• It guarantees causality

• It minimizes sampling bias and improves generalizability

• It ensures the study has no confounds

• It makes descriptive statistics unnecessary

What is the main drawback of convenience sampling?

• It requires too much time and money

• It introduces bias because participants may not represent the population

• It eliminates external validity

• It cannot be used in psychology

Which of the following is an example of sampling bias?

• Recruiting only psychology majors when studying college students in general

• Using a random number generator to select participants

• Assigning participants randomly to conditions

• Measuring participants with both interval and ratio scales

What does generalizability depend on?

• The number of participants alone

• Whether the sample represents the population

• Whether the data are reliable

• The type of statistics used

Stratified random sampling ensures…

• That groups within the population are represented proportionally in the sample

• That only one subgroup is studied

• That convenience participants are used more efficiently

• That every possible variable is controlled

What is oversampling?

• Collecting more participants than required for reliability

• Intentionally sampling more individuals from underrepresented groups

• Using convenience sampling from multiple locations

• Measuring more variables than needed

Which type of validity is most threatened by biased sampling?

• Internal validity

• Construct validity

• External validity

• Content validity

Why do many psychology studies rely on WEIRD samples (Western, Educated, Industrialized, Rich, Democratic)?

• They are the only valid populations

• They are easier and cheaper to recruit (convenience sampling)

• They guarantee generalizability

• They eliminate ethical concerns