PS211 Exam 3
Analysis of variance, family of statistical tests
ANOVA means ____ and is a ____
Subtracting the mean of the population (0 assuming the null is true) from the mean difference and dividing that value by the sample standard error
Cohen's d can be calculated for a paired samples t by ____
Subtracting the mean score in condition 1 from the mean score in condition 2 and dividing that value by s pooled
Cohen's d can be calculated for an independent samples t by ____
Taste-testing
a classic within-groups design is ____
One-way ANOVA
a hypothesis test that includes both one nominal independent variable with more than two levels and a scale dependent variable
Two-way ANOVA
a hypothesis test that includes two nominal independent variables, regardless of their numbers of levels, and a scale dependent variable
Statistical power
a measure of the likelihood that we will reject the null hypothesis, given that the null hypothesis is false
Counterbalancing
a method of controlling for order effects in a repeated measure design by either including all orders of treatment or by randomly determining the order for each subject
Number of participants - 1
a trick to determine the total degrees of freedom is ____
Cohen's d
a very common effect size indicator that expresses effect size in terms of standard deviation; standardized difference between means
Still focusing on a ratio of between-group and within-group variance, same 6-step process, similar assumptions
similarities between ANOVAs and t-tests include ____, ____, and ____
Impossible, unethical, impractical
sometimes within-subjects studies are ____, ____, or ____
Meta analysis
studies that involve the calculation of a mean effect size from the individual effect sizes from multiple studies
Posthoc tests
tests that help you identify where the specific differences are after running an ANOVA
More conservative, can be used in many situations
the Bonferroni correction is ____ and ____
R^2
an estimate of the proportion of variance in the DV that is accounted for by the independent variable
Tukey HSD (honestly significant difference)
determines the differences between the means in terms of standard error
Type II error
failing to reject a false null hypothesis
Source table
helps researchers organize the most important calculations necessary to conduct an ANOVA as well as the final results
Tukey's HSD
if equal variances is not violated, run a ____
Games-Howell
if equal variances is violated, run a ____
Order effects
occur when the order in which the participants experience conditions in an experiment affects the results of the study
Homoscedasticity
population variance in the DV is the same at each level of the IV
Heteroscedasticity
populations are those that have different variances
A significant F statistic is found
posthoc tests can only be run if ____
Bonferroni correction
reduce type I error by dividing alpha by # of tests to give new alpha for finding the t-critical value
Type I error
rejecting null hypothesis when it is true
Partial eta squared
similar to R^2, explains how much variance can be explained by the IV
First finding the grand mean by finding the mean of all values across conditions and finding SStotal, then find SSwithin using the mean of the group that the participant comes from, then find SSbetween using the mean of the group that the participant comes from (same value for each row of each separate group), then find dfbetween, dfwithin, and dftotal, then find the two MS values, and finally divide MSbetween by MSwithin to find the F-statistic
the F-statistic for the one-way between-groups ANOVA can be calculated by ____
First finding the grand mean by finding the mean of all values across conditions and finding SStotal, then find SSbetween using the mean of the group that the participant comes from (same value for each row of each separate group), then find SSsubjects using the mean of each participant's responses across conditions, then find SSwithin, then find dfbetween, dfwithin, dfsubjects, and dftotal, then find the three MS values, and finally divide MSbetween by MSwithin to find the F-statistic (F-subjects isn't important for NHST)
the F-statistic for the one-way within-groups ANOVA can be calculated by ____
Dividing SSbetween by SStotal
the R^2 effect size for the one-way between-groups ANOVA can be calculated by ____
Dividing SSbetween by (SStotal - SSsubjects)
the R^2 effect size for the one-way within-groups ANOVA can be calculated by ____
Unexplained variance
the amount of variation in the dependent variable that cannot be accounted for by the combination of independent variables
F-distribution
the comparison distribution for one-way between-groups and one-way within-groups ANOVAs is the ____
Publication bias
the fact that in the current climate, studies with significant findings are more likely to be published than studies without significant findings
Is the dependent variable scale?, is the data randomly selected from the population?, are the data normally distributed?, do the populations have the same variance? (homoscedastic vs. heteroscedastic), is there counterbalancing?
the five assumptions for a one-way within-groups ANOVA are ____, ____, ____, ____, and ____
Is the dependent variable scale?, is the data randomly selected from the population?, are the data normally distributed?, do the populations have the same variance? (homoscedastic vs. heteroscedastic)
the four assumptions for a one-way between-groups ANOVA are ____, ____, ____, and ____
Select a topic of interest and determine your inclusion criteria, locate ALL studies that meet your criteria, calculate an effect size for each study (often Cohen's d), calculate summary statistics, create a visual display of the effect sizes, and conduct a hypothesis test
the four main steps of meta analysis are ____, ____, ____, and ____
Things that increase the area under the curve beyond the cutoff, things that decrease standard error, things that reduce unexplained variance, things that exaggerate the mean difference between levels of the IV
the main categories of factors that influence power include: ____, ____, ____, and ____
Choose the appropriate hypothesis test, state the null and research hypotheses in words, determine the characteristics of the comparison distribution, determine the critical values, calculate the test statistic, decide whether to reject or fail to reject the null hypothesis
the six main steps of hypothesis testing include: ____, ____, ____, ____, ____, and ____
Differences between means, variance explained
the two main types of effect sizes express the size of the effect in terms of ____ and ____
0.2, 0.5, 0.8
the typical convention for Cohen's d values is that ____ is small, ____ is medium, and ____ is large
0.01, 0.06, 0.14
the typical convention for R^2 values is that ____ is small, ____ is medium, and ____ is large
Increase N, decrease standard deviation
things that decrease standard error include: ____ and ____
Increase alpha, use a one-tailed test instead of a two-tailed test (not relevant for ANOVAs)
things that increase the area under the curve beyond the cutoff include: ____ and ____
Repeated measures ANOVA
this one-way ANOVA uses correlated groups of participants or every participant goes through multiple conditions
Numerator degrees of freedom (between-groups), denominator degrees of freedom (within-groups)
to determine critical values for the F-statistic, use the intersection of the ____ and the ____
Forest plot
type of diagram used to present the meta-analysis results of studies with dichotomous outcomes; plots mean differences
The Levene's Test significance is less than 0.05, the Levene's Test significance is not less than 0.05
when running a one-way between-subjects ANOVA on SPSS, equal variances is violated if ____ and equal variances is not violated if ____
There was a statistically significant difference between groups as determined by a one-way between groups ANOVA, F(2,27) = 4.467, p = .021, ηp2 = 0.12, C: 16.8 - 32.4. The data did not reveal a violation of equal variance, therefore Tukey's HSD post hoc tests were performed. The multiple comparisons found that the time to complete the problem was significantly lower after taking the intermediate (Mean =23.40, SD = 3.20 (min), p =0.03) course compared to the beginners' course (Mean = 27.20, SD = 3.00 (min)). There was no statistically significant difference between the intermediate and advanced groups (p =0 .99). Overall, we find that the effect of preparation as evidenced by the type of course completed can have a significant effect on the amount of time required to solve problems.
when writing up a results section for an ANOVA: ____
Games-Howell
when you have unequal variances and unequal sample sizes, an attractive post-hoc procedure is the
Partial eta squared, eta squared
when you only have 1 IV, ____ and ____ are the same