COM 304 FINAL EXAM QUESTIONS AND VERIFIED
ANSWERS
What are three features of a "true" experiment? - Answers - IV must be manipulated,
randomly assign people to conditions, control of extraneous variables
What are 3 criteria for making causal claims? - Answers - Covariation (have to be
related), time order, alternative explanations
What does it mean to say that another variable might be "confounded" with the IV? -
Answers - 3rd factor also occurs with independent variable so you can't tell which is
actually causing the DV
How do you prevent confounding? - Answers - Control everything except manipulation
of IV
What is a spurious relationship? - Answers - When two variables have no direct causal
relationship but may be inferred bc of presence of a 3rd factor
What is internal validity? - Answers - High level of control within experimental study
What is external validity? - Answers - generalizability
Can a study be high in internal and external validity? - Answers - No
What are three types of distributions? - Answers - Population, sample, sampling
Population distribution - Answers - The distribution of values of the variable among all
the individuals in the population.
sample distribution - Answers - frequency distribution of all the elements of an individual
sample
sampling distribution - Answers - frequency distribution of sample statistics (e.g.,
sample means) for multiple samples of a given size which all were drawn randomly from
a larger population
3 ways of describing sampling distribution of means - Answers - central tendency,
shape, and dispersion
How can we describe the central tendency for a sampling distribution of means? -
Answers - mean of distribution of sample means (Mm)
ANSWERS
What are three features of a "true" experiment? - Answers - IV must be manipulated,
randomly assign people to conditions, control of extraneous variables
What are 3 criteria for making causal claims? - Answers - Covariation (have to be
related), time order, alternative explanations
What does it mean to say that another variable might be "confounded" with the IV? -
Answers - 3rd factor also occurs with independent variable so you can't tell which is
actually causing the DV
How do you prevent confounding? - Answers - Control everything except manipulation
of IV
What is a spurious relationship? - Answers - When two variables have no direct causal
relationship but may be inferred bc of presence of a 3rd factor
What is internal validity? - Answers - High level of control within experimental study
What is external validity? - Answers - generalizability
Can a study be high in internal and external validity? - Answers - No
What are three types of distributions? - Answers - Population, sample, sampling
Population distribution - Answers - The distribution of values of the variable among all
the individuals in the population.
sample distribution - Answers - frequency distribution of all the elements of an individual
sample
sampling distribution - Answers - frequency distribution of sample statistics (e.g.,
sample means) for multiple samples of a given size which all were drawn randomly from
a larger population
3 ways of describing sampling distribution of means - Answers - central tendency,
shape, and dispersion
How can we describe the central tendency for a sampling distribution of means? -
Answers - mean of distribution of sample means (Mm)
