FREE Psychology Degree Psychological Research Methods Questions and Answers Flashcards

A researcher wants to determine whether sleep deprivation causes decreased reaction time. Which research design is most appropriate?

Answer: True experiment with random assignment

A true experiment with random assignment allows the researcher to manipulate the independent variable and establish causation.

What is the primary purpose of a double-blind procedure in psychological research?

Answer: To reduce demand characteristics and experimenter bias

Double-blind procedures prevent both participants and researchers from knowing group assignments, reducing bias from both sources.

Which measure of central tendency is most affected by extreme scores in a data set?

Answer: Mean

The mean is calculated using all values in the distribution, making it highly sensitive to outliers.

In a study examining the relationship between anxiety and test performance, anxiety level is the independent variable and test score is the dependent variable. What type of validity is threatened if the anxiety manipulation also unintentionally changes participants' motivation?

Answer: Internal validity

Internal validity is compromised when a confounding variable like motivation co-varies with the independent variable.

A psychologist surveys 500 college students about their study habits and GPA. Which correlation coefficient indicates the strongest relationship?

Answer: r = -0.87

The strength of a correlation is determined by its absolute value, and 0.87 is the largest regardless of direction.

Which sampling method gives every member of the population an equal chance of being selected?

Answer: Simple random sampling

Simple random sampling ensures each individual has an equal probability of selection, minimizing sampling bias.