Stats Anova

ANOVA is an ________ test

Omnibus

Three characteristics of a One-Way ANOVA

One IV, One DV, Three or more levels of the IV

MS equation

SS/df

individual score from groups score

SSe

Individual difference, measurement wrrot

SSe (Sum of Squares Error)

Individual score from total mean

SSt

Variability among all scores on the DV

SSt

What is F?

Test statistic for ANOVA

k=

number of groups

How is F calculated?

MSb/MSe (Between group variance/Error Variance(MS))

4 Assumptions to complete the one-way between-subjects ANOVA

Normality Random Sampling Independence Homogeneity of Variance

more than one IV and DV

Factorial MANOVA

Why wouldn't you use separate t-test for more than two levels of the IV?

It would increase the Type 1 error to something above 5%

A one-way within-subjects ANOVA is typically associated with _____ power than the one-way between-subjects ANOVA.

Larger

The effect of the IV

SSb (Sum of Squares Between)

What is the typical effect size used with ANOVA?

SSb/SSt

The post hoc test controls against making what type of error?

Type 1, keeps alpha at 0.05

The same participants are measured in each level of the IV

Within-Subjects ANOVA

For the one-way within-subjects ANOVA, the more ________ participant responding between groups, the less powerful the test will be at detecting the effect

inconsistent

Without changing the value of error variance, the _________ between-groups variability, the more likely we are to reject the null hypothesis.

larger

The term "between-subjects" refers to A. Observing different participants one time in each group B. The type of post hoc conducted C. The type of effect size estimate measured D. Observing the same participants in each group

A

T/F As mean square error decreases, power decreases

False

A researcher measures anxiety levels among participants in the presence and absence of a fearful stimulus. If the same participants are observed in each group, then what type of statistical design is appropriate for this study? A. Related-Samples t test B. A one-way between-subjects C. A one-way within-subjects D. both A&C

D

The turkey HSD post hoc test only works for what?

Equal group sizes

F

MSb/MSe

T/F To conduct a one-way between-subjects ANOVA, we assume that the samples were randomly selected from populations with equal variances, and that participants were independently observed in each group.

True

If the experiment is successful...

then the model will explain more variance than it can't (SSb will be greater than SSe)

ANOVA stands for...

analysis of variance

For an analysis of variance, the term "one-way" refers to.. A. The number of statistical tests in the design B. The number of factors in the design C. The direction that traffic should follow on a road D. The number of ways that the data can be analyzed.

B

Homogeneity of variance is an assumption for the one-way between-subjects ANOVA. What does this assumption mean? A. That the population being sampled from is normally distributed B. That the variance is equal in each population from which samples are selected C. That one observation has no effect on the likelihood of another observation D. That participants are randomly selected to participate in a sample

B

A researcher divides participants into groups that will engage in low, moderate, or intense levels of exercise. The total calories consumed by participants following the exercise are then recorded. What type of statistical design is appropriate for the study? A. Related-Samples t test B. A two-independent sample t-test C. A one-way between subjects ANOVA D. Both B&C

C

Computing a one-way between-subjects ANOVA is appropriate when A. the levels of one or more factors are manipulated B. The same participants are observed in each of two or more groups for one factor C. Different participants are observed one time in each of two or ore groups for one factor D. all of these

C

Computing a one-way within-subjects ANOVA is appropriate when A. different participants are assigned to each group B. the levels of one or more IV are manipulated C. The same participants are observed across groups D. All of these

C

T/F A post hoc test is only necessary following a decision to retain the null hypothesis

False

Group mean from the total mean

SSb

The term "one way" means that you are testing...

one factor

F=

t^2

3 reasons why ANOVA is omnibus

1. Tests for overall difference 2. Tell us the group means are different 3. Doesn't tell us exactly which means differ

The source of variability associated with error variance in the one-way between-subjects ANOVA is called... A. Within-groups variability B. Between-groups variability C. Degrees of freedom D. both A&B

A

Post hoc tests are computed A. prior to conducting a hypothesis test B. following a significant ANOVA test to make pairwise comparisons C. To determine which set of degrees of freedom can be attributed to the variability between groups D. To determine if groups means differ, even for tests in which decision is to retain the null hypothesis

B

There are two sources of variation in a one-way between-subjects ANOVA: one attributed to differences between groups and one attributed to error. T/F

True

more than one DV

one-way MANOVA

Used when different participants are measured in each level of the IV

one-way between subjects

T/F An ANOVA is used when samples are selected from two or more populations and when two or more samples are selected from the same population.

True

How many sources of error are present in a one-way within subjects ANOVA?

2

A researcher compares differences in positivity between participants in a low-, middle-, or upper middle-class family. If she observes 15 participants in each group, then what the degrees of freedom for the one0way between subjects ANOVA?

2, 42

Which of the following is an assumption for computing a one-way between-subjects ANOVA? -One observation has no effect on the likelihood of another observation -Participants were selected to participate using a random procedure -The population being sampled from is normally distributed -All of the above

All of the above

"Within subjects" is also called... A. Random Sampling B. Repeated Measures C. Within-groups D. Between-subjects

B

Anova with 2 IV's

Two-way ANOVA

Following a significant one-way between subjects ANOVA in which k > 2, what is the next appropriate step? A. interpret the data; no further tests are required B. Summarize the data; no further tests are required C. Conduct post hoc tests D. both A&B

C