Summa Week 12 Flashcards
The _________________ t-test evaluates whether two independent groups or samples come from the same population
independent-samples t-test
A one-way between-subjects ANOVA is a generalization of a __________ t-test, and asks whether ___ or more (k) groups or samples come from the same ______
independent-samples t-test
three
population
What would a chart for a 1-way anova look like?
Subject Treatment 1 Treatment 2 Treatment 3
Subject 1 Subject 1 Subject 1 Subject 1
Subject 2 Subject 2 Subject 2 Subject 2
one-way anova summary table: between subjects
between group SSbetween?
dfbetween * MSbetween
one-way anova summary table: between subjects
dfbetween?
k - 1 (k = number of treatments)
one-way anova summary table: between subjects
MSbetween?
SSbetween/(k-1)
one-way anova summary table: between subjects
F-value?
MSbetween/MSwithin(or error)
one-way anova summary table: between subjects
SSerror?
dferror*MSerror
one-way anova summary table: between subjects
dferror?
N-k
one-way anova summary table: between subjects
MSerror?
SSerror/(N-k)
one-way anova summary table: between subjects
SStotal?
SSbetween subjects + SSerror
one-way anova summary table: between subjects
dftotal?
dfbetween + dferror
What is the design for using a One-way within-subjects ANOVA?
subjects undergo multiple conditions over time
What is the most powerful analysis for a 2-sample design?
matched-pair samples t-test
what is required for the matched-pair samples t-test to be the most powerful analysis for a 2-sample design?
if the samples are correlated. If they aren’t, then you can’t assume the difference is due to the conditions
True or false: repeated-measures designs (ANOVA) ask whether three or more (k) correlated groups or samples come from the same population.
True!
True or false: A One-way within-subjects ANOVA is a generalization of an independent samples t-test.
False! it is a generalization of a matched-pair samples t-test.
True or false: Repeated measures design can use family members instead of the same participants in research.
true. although the same participants is more helpful, similar individuals can be replaced, which refers to the whole “matched-pairs” idea
What does the one-way within-subjects ANOVA summary table look like, particularly for between subjects?
between/inter-subjects
SS between subjects / SSs / dfb (n-1) / MSb = NO F-VALUE OF INTEREST
What does the one-way within-subjects ANOVA summary table look like, particularly for treatment calculations?
treatment / differences due to treatment
SStreatment / SStreatment / dftreatment (k-1) / MStreatment / F=MStreatment/MSerror
What does the one-way within-subjects ANOVA summary table look like, particularly for error?
error = within/intra-subjects (individual) differences
Sourceerror / SSerror / (n-1)(k-1) / MSerror = NO F-VALUE CALCULATED
What is the difference between dfbetween for one-way between-subjects ANOVA and df between for one-way within-subjects ANOVA?
dfbetween-subjects = N-k dfwithin-subjects = (n-1)(k-1)
What does the one-way within-subjects ANOVA summary table look like, particularly for total SS?
Source total / SStotal / dftotal (n*k-1)
What is the difference between dftotal for one-way between-subjects ANOVA and dftotal for one-way within-subjects ANOVA?
dftotal between-subjects = N-1
dftotal within-subjects = n*k-1
Why are repeated-measures designs often more powerful?
because participants are measured more than one in order to better detect the individual differences and remove them from the analysis
How do you find individual differences in one-way within-subjects ANOVA?
subtracting them from the error term
What is the formula for repeated-measures design ANOVA (SS)?
SStotal = SSbetween subjects + SSwithin subjects (between treatments) + SSerror (individual differences)
What is the F-value for between-subjects in a one-way within-subjects ANOVA?
who cares? it isn’t relevant
What is the F-value for within-subjects in a one-way within-subjects ANOVA?
MSwithintreatment/MSerror(individual differences)
What the hell is Sphericity assumption?
tests for the null hypothesis that the error covariance matrix of the orthonormalized transformed dependent variables is proportional to an identity matrix (i.e. they are likely to occur from the same population)
What happens if a hypothesis of sphericity is not rejected (p > .05)?
we can conclude that sphericity assumption WAS met, and continue with repeated-measures ANOVA analysis
How do you determine covariance for subjects in a repeated-measures ANOVA design?
checking for assumption of Mauchly’s Test of Sphericity before reporting ANOVA results
What does Howell say sphericity assumption is?
the population variances of the repeated measurements are equal; the population correlations among all pairs of measures are equal
If a violation of the assumption of sphericity occurs, just write that it may have happened in results
False. It is a serious concern, which increases the potential for Type I error, so use a different estimate in determining new family-wise error for analysis
What are two estimates that can modify the severity of violation of sphericity assumption?
Greenhouse-Geisser, Huynh-Feldt and Lower-bound estimate
Which is more conservative: Greenhouse-Geisser or Huynh-Feldt for violation of sphericity assumption adjusted estimates?
Greenhouse-Geisser
What do you multiuply adjusted estimates of sphericity assumption by to correct for the effect of sphericity?
degrees of freedom
What do we assume about normality in one-way within-subjects ANOVA?
we assume they are normally distributed
What do we assume about independence in one-way within-subjects ANOVA?
it is NOT assumed that the scores are independent, since that’s what we’re basing our design off of
What does a one-way within-subjects ANOVA gave>?
Source SS df MS F
(Between) Subjects 486.11 8 - -
Treatment 2449.20 4 612.30 85.04
(Within)Error 230.40 32 7.20 -
Total 3166.31 44 - -
What are tests supplementing a within-subjects ANOVA similar to?
those for between-subjects ANOVA!
What is the difference in supplemental tets for within-subjects ANOVA and between-subjects ANOVA?
in the computational details in SPSS
True or false: When specific comparisons among means are made on between-subjects variables, an error term for each specific comparison is calculated. The same error term is used for all comparisons when the variable is within-subjects design.
False!
within-subjects variables need to compare each error term, whereas between-subjects designs are universally compared with the same error term
True or false: it is easy to explain if you have significant higher-order trends in within-subjects design.
Hell naw
Which factor do you use when reportin the results of within-subjects contrasts?
a) cubic
b) linear
c) quadratic
d) order 4
b) linear??????
What is another name for order effects?
trial effects