QAC 201 Exam 3
Covariate - answer A variable that is possibly predictive of the outcome under study
Confounder - answer A variable that is related to both the treatment and the outcome
Moderator - answer A third variable that, depending on its level, changes the
relationship (strength or direction) between two other variables.
Volunteer sample - answer Consists of people who are willing to volunteer for a study
Convenience sample - answer A form of nonprobability sample using respondents who
are convenient or readily accessible to the researcher—for example, employees,
friends, or relatives
Simple random sample (SRS) - answer A sample where n individuals are selected from
a population in a way that every possible combination of n individuals is equally likely
Cluster sampling - answer A probability sampling technique in which clusters of
participants within the population of interest are selected at random, followed by data
collection from all individuals in each cluster.
Stratified sampling - answer A type of probability sampling in which the population is
divided into groups with a common attribute and a random sample is chosen within
each group.
Observational study - answerObserves individuals and measures variables of interest
but does not attempt to influence the responses
Experimental study - answerResearcher manipulates one of the variables and tries to
determine how the manipulation influences other variables
independent variable - answervariable that is manipulated
dependent variable - answerthe outcome factor; the variable that may change in
response to manipulations of the independent variable.
Linear regression - answerA statistical method used to fit a linear model (line of best fit)
to a given data set
Covariate - answer A variable that is possibly predictive of the outcome under study
Confounder - answer A variable that is related to both the treatment and the outcome
Moderator - answer A third variable that, depending on its level, changes the
relationship (strength or direction) between two other variables.
Volunteer sample - answer Consists of people who are willing to volunteer for a study
Convenience sample - answer A form of nonprobability sample using respondents who
are convenient or readily accessible to the researcher—for example, employees,
friends, or relatives
Simple random sample (SRS) - answer A sample where n individuals are selected from
a population in a way that every possible combination of n individuals is equally likely
Cluster sampling - answer A probability sampling technique in which clusters of
participants within the population of interest are selected at random, followed by data
collection from all individuals in each cluster.
Stratified sampling - answer A type of probability sampling in which the population is
divided into groups with a common attribute and a random sample is chosen within
each group.
Observational study - answerObserves individuals and measures variables of interest
but does not attempt to influence the responses
Experimental study - answerResearcher manipulates one of the variables and tries to
determine how the manipulation influences other variables
independent variable - answervariable that is manipulated
dependent variable - answerthe outcome factor; the variable that may change in
response to manipulations of the independent variable.
Linear regression - answerA statistical method used to fit a linear model (line of best fit)
to a given data set
