RESEARCH CHAP. 14

a study investigated the influence of relaxation training. and type of sleep inducing product on the amount of time it takes a person to fall asleep. partial results from the data analysis are in the table below. Compute the effect size for the relaxation factor.

0.37

a study investigated the influence of age and time pressure on creativity. Summary statistics are presented below. There was a significant main effect of time pressure. With MS=2.89 compute the HSD for the difference between 30 seconds and 2 minutes. Use a=0.05

1.04

if EX=49, EX2=104...=85,...=90, SSbn=17.55 and N=30 what is SSaxb?

2.61

if EX=49. ex2=104 and N=30 what is SStot?

23.97

if EX=49, EX2=104....=85

4.97

in a 3x4 design with four participants per cell, the degrees of freedom to use in looking up the Fcrit for the interaction effect would be

6,36.

if EX=49, EX2=104...=85,...=90, SSbn=17.55 and N=30 What is SSmn?

6.42

How many participants would be required for a completely randomized 4x5 between subjects design with three observations per cell

60

if EX=49, EX2=104 ....=85, ...=90 and N=30 what is SSb?

9.97

In a two way analysis of variance where Factor A has 3 levels and Factor B has 4 levels, what are the appropriate df is 240 participants are evenly distributed among the treatments?

B

A study investigated the influence the age and time pressure on creativity. The HSD for the interaction effect was 1.76. The table below shows the absolute differences between the cell means. Where are the significant differences?

Between the mean for participants over 65 at the 30 sec time pressure and the mean for over 65 at the 2 min time pressure.

for which of the three f tests in a two way ANOVA do you collapse across the levels of the other factors in computing the means

Both the A main effect and the B main effect

suppose you perform a 2x3 ANOVA on 18 participants equally divided across all cells. your F obt for factor A is 9.15. This is a significant Fobt. Which of the following is the correct way to report this finding?

Fa(1,12)=9.15 ; p<0.05

in a two way ANOVA, the hypotheses for a Factor B that has four levels are

Ho:uB2=UB2=UB3-UB4: not all bus are equal

For the following mean square from an ANOVA summary table what are the correct Fobt values?

a

a two way ANOVA contains

a main effect for each factor and an interaction

The primary interpretation of a two way ANOVA rests on the interpretation of the

interaction effect, if it is significant

In a 2x2 design with 40 participants equally distributed across the conditions, what are Ka and Na1?

ka=2; na1=20

the denominator in the all F ratios in a two way factorial ANOVA is

the estimate of the variability within any of the raw score populations represented by the samples

a professor and his graduate students conducted a study testing the effects of levels of collaborative learning and levels of constructivist instruction on student learning. Their partial summary table is shown here. What was Fa?

Fa=10

A study investigated whether taking a test in the same room in which a person studies helps performance on the test. The means are below. Which of the graphs correctly portrays the interaction?

Graph B

in a 4x2 design with 80 participants distributed equally across the conditions, what are Kab and Na1b1?

Kab=8 Na1b1=10

sarah ann designed, conducted, analyzed, wrote, and published an experiment. In the 2x4 ANOVA, the F value for Art Medium was Fa=8.8, indicating a significant difference in the time it took to produce works of art using different media. The F value for size of the art work was Fb=1.2 indicating a nonsignificant finding. The interaction also was nonsignificant. What was the dependent variable?

Time

for factor A, you have times the rate at which participants can solve puzzles under three conditions of noise: high, medium, and low. In addition, for factor B the participants have received either no caffeine or a high level of caffeine (equivalent to 4 cups of coffee) what kind of design do you have?

a 3x2 between-subjects, factorial design

if you are interested in how well students perform on a standardized math achievement test after they have completed a six week math unit in either a computer assisted class, a videotaped course, or a regular classroom, what kind of design do you have?

a one way design

In any two way ANOVA, if Faxb is significant. which of the following is true

a significant interaction does not tell us anything about the significance of the main effects.

A complete factorial design occurs when

all levels of one factor are combined with all levels of the other factor

When graphed, a significant interaction effect produces two or more lines that

are not parallel

In a two way ANOVA, the HSDs for the two main effects will

be different if their ks and ns are different

For the following two way ANOVA summary table what are the appropriate MS values?

c

Sharon has conducted a study on the effectiveness of a drug for obsessive-compulsive disorder (OCD). Her drug levels are 0 mg. 100 mg, and 500 mg. She also has included a second factor of therapy versus no therapy. Sharon already has computed the goal of the scores in each treatment. These are given below, along with the sum of the scores for every measurement in the study (EX) Sharon has 10 participants in each treatment condition. What is her Fa (drug level)? and (Fb therapy levee?) and what is her FaxB?

drug level 87.01, and therapy level 34.64 and Faxb is 7.25

In a two way ANOVA, the main effect of a factor is the

effect of changing the levels of the factor on the dependent variable scores, ignoring all other factors in the study

we do not compare cell means in post hoc analysis when the cells are confounded because

even if the difference were significant, we could not tell where it came from

In a two way ANOVA, the interaction effect is the

extent to which the effect of one factor depends on the action of the other factor

The graph a main effect from a two way ANOVA, the _____is (are) plotted along the x axis, the ____is plotted along the Y axis and the ___ is plotted in the graph.

levels of a factor; dependent variable;main effect means

To graph an interaction, place the____on the x axis, place the_____ along the y axis and show the second factor by____.

levels of one factor; dependent variable; drawing a separate line for each level of the second factor, with each line connecting the means for the levels

in a two-way ANOVA, the values of n and k

may be different for each factor.

Usually the effect size for any significant effects in a two way ANOVA is determined by computing_____, the proportion of variance accouted for in the sample.

n2

The primary reason for conducting a study with two factors is to

observe the interaction between the factors

in a two-way ANOVA, a cell represents

one level of A independent variable and one level of the B independent variable

If you have a two way ANOVA with 2x3 design, and A main effect is the only significant Fobt which of the following would you do?

perform no post hoc comparisons

If n2 for a factor is 0.09

the factor accounts for 9% of the variance in scores.

A significant interaction effect indicates that

the influence of one factor is not the same for each level of the other factor.

An interaction effect that is NOT significant indicates that

the influence of one factor is the same for each level of the other factor

in a two way ANOVA, an F involving a comparison among the means of the cells is referred to as a test of the significance of

the interaction effect

In a two-way ANOVA, an F involving a comparison among the level means of a factor is referred to as a test for the significance of

the main effect

which of the following is not one of the assumptions we must satisfy when conducting a two way between subjects ANOVA

the means of all the populations represented are equal

The larger the value of n2

the more important the manipulation (independent variable) is in determining participants scores

The" adjusted k" in Turkeys HSD in adjusted to take into account

the number of unconfounded comparisons we can make out od all the cell means in our interaction

If you are interested in how well students perform on a standardized math achievement test after they have completed a six week math unit in either a computer assisted class a videotaped course or a regular classroom, and you also want to include a factor for sex (boys vs. girls) what is the dependent variable?

the scores on the math achievement tests

a confounded comparison occurs in comparing two cell means when

the two cells differ along more than one factor.

an unconfounded comparison occurs in comparing two cell means when

the two cells differ along one factor

The Ho for a main effect of a two way ANOVA is that the samples in the various levels are drawn from populations where

there are equal means

when an experiment design has two factors but one factor involves related samples while the other factor involves independent samples we should perform a

two-way mixed-design ANOVA

when an experiment design has two factors but one factor involves related samples while the other factor involves independent samples, we should perform a

two-way within subjects ANOVA

In statistical terminology, when we "collapse across a factor," we average together all the scores

within each level of a factor, ignoring which level of the other factor they fall into.