PSYCH 209 FINAL EXAM
An association that involves exactly two variables. Also called "bivariate association".
Bivariate correlation
An arithmetic average; a measure of central tendency computed from the sum of scores in a set
of data, divided by the total number of scores.
Mean
A statistical test used to evaluate the size and significance of the difference between two
means.
T-test
The magnitude, or strength, of a relationship between two or more variables
Effect size
A researcher's assessment of whether a result from a sample (such as an association or a
difference between groups) could have come from a population in which there is no association
or no difference. When the sample's result is extreme, it would rarely be found in such a
population and is said to be statistically significant.
Statistical significance
A score that stands out as either much higher or much lower than most of the other scores in a
sample.
Outlier
In a bivariate correlation, the absence of a full range of possible scores on one of the variables,
so the relationship from the sample underestimates the true correlation.
Restriction of range
, An association between two variables which is not a straight line; instead, as one variable
increases, the level of the other variable increases and then decreases (or vice versa). See also
positive association, negative association, zero association.
Curvilinear association
In a correlational study, the occurrence of both variables being measured around the same
time, making it unclear which variable in the association came first.
Directionality problem
In a correlational study, the existence of a plausible alternative explanation for the association
between two variables. See also, internal validity.
Third-variable problem
A bivariate association that is attributable only to systematic mean differences on subgroups
within the sample; the original association is not present within the subgroups.
Spurious association
A variable that, depending on its level, changes the relationship between two other variables.
Moderator
A study in which one variable in manipulated and the other is measured
Experiment
A variable in an experiment that a researcher controls, such as by assigning participants to its
different levels (values).
Manipulated variable
A variable in a study whose levels (values) are observed and recorded.
Measured variable
An association that involves exactly two variables. Also called "bivariate association".
Bivariate correlation
An arithmetic average; a measure of central tendency computed from the sum of scores in a set
of data, divided by the total number of scores.
Mean
A statistical test used to evaluate the size and significance of the difference between two
means.
T-test
The magnitude, or strength, of a relationship between two or more variables
Effect size
A researcher's assessment of whether a result from a sample (such as an association or a
difference between groups) could have come from a population in which there is no association
or no difference. When the sample's result is extreme, it would rarely be found in such a
population and is said to be statistically significant.
Statistical significance
A score that stands out as either much higher or much lower than most of the other scores in a
sample.
Outlier
In a bivariate correlation, the absence of a full range of possible scores on one of the variables,
so the relationship from the sample underestimates the true correlation.
Restriction of range
, An association between two variables which is not a straight line; instead, as one variable
increases, the level of the other variable increases and then decreases (or vice versa). See also
positive association, negative association, zero association.
Curvilinear association
In a correlational study, the occurrence of both variables being measured around the same
time, making it unclear which variable in the association came first.
Directionality problem
In a correlational study, the existence of a plausible alternative explanation for the association
between two variables. See also, internal validity.
Third-variable problem
A bivariate association that is attributable only to systematic mean differences on subgroups
within the sample; the original association is not present within the subgroups.
Spurious association
A variable that, depending on its level, changes the relationship between two other variables.
Moderator
A study in which one variable in manipulated and the other is measured
Experiment
A variable in an experiment that a researcher controls, such as by assigning participants to its
different levels (values).
Manipulated variable
A variable in a study whose levels (values) are observed and recorded.
Measured variable
