stat exam 3

T or F: F is the ratio of MSgroup dvided by MSerror

true

T or F: a chi-square test compares the observed frequencies with the expected frequencies

true

T or F: an ANOVA is used to compare the means of two of more groups

true

T or F: the odds refer to the frequency of occurrence of one event divided by the frequency of occurrence of another event

true

a within-subject design is when the same participants serve in the same conditions

true

a repeated-measures analysis of variance differs from a one-way and a factorial design because

-the measures in a repeated-meas design are correlated -the measures in a one way and factorial are independent -the measures in a repeated-measures design are not independent from time to time

if we run six independent comparisons among means, each at five percent level, the overall familywise error rate will be approximately

.30

a researcher found significant differences in the mean running speeds of sprinters wearing shoes made by Nike, Reebok, and Adadis using an analysis of variance. the n^2 calculated on the basis of group membership (based on which shoes were worn) equaled .16. the value of n^2 shows that:

16% of the variability in running speed is attributed to shoe brand

a 2 x 2 factorial has

2 levels of one variable and 4 levels on the other

A researcher wants to test if treatment adherence (Adhere/Not Adhere) is related to the number of chronic conditions (One condition/ More than one).

Contingency Table Chi-square test

T or F: measuring the height of the same group of children every year for three years is an example of a between-subjects design

False

the major advantage of repeated-measures designs is that

they allow you to remove subject differences from the error term

If research finds out that the effect of the type of program (online vs. Face-to-face) on performance depends on the instruction modality (synchronous vs. asynchronous), we can determine that:

The interaction effect between type of program and instruction modality is significant

the chi-square test deals with

frequency data

a pediatrician is studying weight gain in infants. he divides them into 2 groups: breastfed and bottle-fed (Fed). further, he divides them into those whose mothers feed them on a timed schedule, and those whose mothers feed them when they cry (scheduled). Weight gain is the department measure. What type of analysis should you run?

a 2 x 2 factorial ANOVA

a type of chi-square test in which we have two categorical variables and is used to test if both variables are associated is

a contingency table chi-square test

(reread the question about alcohol consumption and the videotape) What type of statistical analysis would be most appropriate for the experiment?

a factorial analysis of variance

we want to compare the scores of different groups on a measure of reaction time. Three different groups were studied: patients with recent head injuries, patients with old head injuries, and a control group of non-injured people. we want to know which group of people has the fastest reaction time. What is the best statistical test to use to find this out?

a one-way ANOVA

a goodness-fo-fit chi-square test is used with

a single categorical variable

Gender p=.000 group p=.000 Gender x Group p=.021 which of these is statistically significant?

all of the above

the major disadvantage of repeated-measures designs is that they

are subject to the influence of carry-over effects

when we reject the null hypothesis in the analysis of variance we can conclude that

at least one of the means is different from at least one other mean

A bakery owner suspects that some of his cake flavors are more popular than others. the bakery specializes in three flavors: red velvet, birthday cake, and banana walnuts. the following table shows the number of cakes sold during last weekend. what chi-square should we run to test if one cake is sold more frequently than the others?

goodness-of-fit chi-square test

the chi-square test is used when we have:

categorical variables

a researcher was interested in examining if wearing a face mask (yes/no) is contingent or conditional to the persons' age (young/adult). to test if these variables are independent of one another, what test should the researcher use to analyze the data?

contingency table chi-square test

a researcher wanted to test how watching movies influenced subjects' IQ scores. She gave an IQ test to subjects following watching two movies. half of the subjects first saw Titanic followed by Schindler's List, while the other half first saw Schindler's List and then Titanic. Varying the movie order is an example of:

counterbalancing

the major difference between t tests and the analysis of variance is that the latter:

deals with multiple groups (2 or more groups)

counterbalancing is a technique to

distribute carry-over effects evenly across the data

the bonferroni procedure controls error rates by:

dividing the significance level (alpha) by the number of tests

When comparing differences in an experiment with two or more independent variables, which of the following test is more suitable?

factorial ANOVA

when comparing differences in an experiment with two of more independent variables we should use a(n):

factorial design

T or F: the mean difference in GPA based on gender and year in school is an example of the main effect

false

a factorial analysis of variance has:

more than one independent variable

a repeated-measures ANOVA differs from a paired sample t test in that the paired sample t test only deals with:

more than three times or conditions

analysis of variance differs from t-test in that, ANOVA compares

more than two means

a repeated-measures design is _________ than the corresponding between-subjects design

most powerful

An important assumption in the one-way analysis of variance is that

observations are independent

that goodness-of-fit statistic is used when we have, how many categorical variables?

one

A regional manager was interested in examining the difference in the mean of sales profit of three stores: Store 1, Store 2, and Store 3. What statistical test would be the most appropriate to test differences between the three means?

one-way ANOVA analysis

in the analysis of variance, if we get a sig. F-stat, we need to conduct which follow up test to determine the differences between groups

post hoc tests

in multiple comparison procedures, post-hoc tests are completed after the ANOVA. why are post-hoc tests preferred over running several t-tests?

post-hoc decreases the probability of a Type 1 error

What type of design represents a study in which we collected data from individuals who participated in a parenting program at three moments in time (Pre, Post, Follow-up)?

repeated measures

a _________ design is one in which subjects are measured repeatedly over time

repeated-measures

You want to run a study to examine the effects of poverty on the development of antisocial behavior. you randomly select a large group of 12-year-old children and sort them into three groups on the basis of family income. you meet with them every two years until they reach 20 years old, and measure antisocial behavior using a standard assessment. what test should you run to analyze this data?

repeated-measures ANOVA

the MSerror in a repeated measures design is ___________ than the corresponding MSerror in a between-subjects design

smaller

the main effect is defined as

the effect of one independent variable averaged across the level of the other independent variable

you should be careful about using a chi-square test when

the expected frequencies are quite small (less than 5)

in a chi-square test the expected frequency is

the frequency you would expect if the null hypothesis were true

a researcher tested the effect of 3 different aversive conditions on fear. a group of 15 individuals participated in the 3 different conditions after which their fear was measured. the repeated measure ANOVA result was: F(2, 13)= 4.42, p=.034. what can we conclude?

the participants' fear differs significantly over the three conditions

in the analysis of variance we will assume that:

the populations are normally distributed

the difference between a one-way analysis if variance and a factorial analysis of variance is

the presence of an interaction and the presence of more than one main effect

the familywise error rate is

the probability of a least one Type 1 error

in the analysis of variance with three groups the null hypothesis is:

the three population means are equal to each other

a researcher was interest in the following effects of 1) alcohol consumption 2) the content of a future expectations videotape, on the intention to quit school of male college students. the researcher randomly assigned 60 college aged males to one of the following three groups (based on their responses to a previous questionnaire). no alcohol consumed, a moderated amount of alcohol consumed, a large amount of alcohol consumed. additionally, half of the participants were shown an educational video about future expectations, the other half of the participants watched a documentary about owls (a controlled condition). at the end of the study all of the participants filled out a survey related to intention to drop out of school, higher scores on survey indicated higher intentions to leave school. the results indicate that the participants who watched the educational video scores sig. lower on the intention to drop out of school compared to the group that watched the owl video: what does this suggest?

there is a significant main effect on videotape.

in a repeated-measures ANOVA, the tests to correct the degrees of freedom, such as Greenhouse-Geisser and Huynh-feldt, should be used if:

you forget the assumptions of constant correlations