Quiz #2 Flashcards
expected relative frequency
what you expect to get in the long run if you repeat the experiment many times (AKA long-run relative frequency)
subjective interpretation of probability
how certain we are that a particular thing will happen
research hypothesis
a prediction about the difference between populations
null hypothesis
a statement about the lack of difference between populations
comparison distribution
the probability of getting the result that you got (AKA sampling distribution)
cutoff score
how extreme the sample score would have to be to be too unlikely if the null hypothesis were true (AKA critical value)
one tailed test
tests directional hypothesis (when researchers are only interested in one direction of result)
two tailed test
test nondirectional hypothesis (when a research hypothesis predicts an effect but not the direction of that effect)
t test
hypothesis testing procedure where the population variance is unknown
single sample t test
used when you have the scores for a sample of individuals and want to compare the mean to a population where you know the mean but not the variance (AKA one-sample t test)
t test for dependent means
procedure for a repeated measures design (when you have two scores for each person in your sample) (AKA paired-samples t test)
ANOVA
procedure for testing variation among the means of more than two groups (AKA analysis of variance)
F ratio
the ratio of the between-groups to the within-groups population variance estimate
planned contrasts
comparison where the particular means were decided in advance
posthoc comparisons
multiple comparisons not specified in advance
type I error
the null is true but you reject it
type II error
the null is false but you accept it
criteria to causality
covariation (requires the causal variable to be related to the effect variable), time precedence of the cause (cause must come before the effect), absence of alternative explanations
systematic variance
between groups; deviation of group means from the grand mean (want large difference)
error variance
within groups; deviation of scores in each group from the respective group (want small difference)
event
an observable outcome
generating event
process you go through to observe an event
multiplication theorem
and
addition theorem
or
