A(n) ________ occurs when ________ independent variable(s) have an effect in combination with one another. interaction; two or more interaction; two or less main effect; two or more main effect; two or less 2.5 points Interested in the effects of different kinds of instruction on videogame performance, Martin asks 30 college freshmen to each play an hour of Ratchet and Klank. Participants are randomly assigned to one of three instruction groups: (1) complete the tasks as quickly as possible, (2) conserve as much health as possible (i.e., play more carefully), or (3) find gold bolts (worth lots of money in equipment and ammunition). If Martin averages the scores for each instruction group and then compares them, any differences in the means of the instruction groups reflect: individual differences in hand-eye coordination. inherent differences in the ability of the college freshmen to play video games. within-groups variance. between-groups variance. 2.5 points Why can’t a researcher just run multiple t tests when the independent variable has more than two levels? As you run more statistical tests, it becomes harder and harder to reject the null hypothesis. As you run more statistical tests, the probability that you will make a Type I error in one of the tests increases. As you run more statistical tests, you lose degrees of freedom. As you run more statistical tests, the probability that you will make a Type III error in one of those tests increases. 2.5 points ________ is a term used to describe an independent variable in a study with more than one independent variable. Interaction Main effect Effect Factor 2.5 points (Table: Coping with Pain) The cells of this study reflect an interaction between coping style and cognitive strategy. Which statement best describes the interaction? People using both distraction and sensation-monitoring cognitive strategies were able to keep their hand in the ice water for longer than 60 seconds, on average. People using a sensation-monitoring strategy were able to keep their hand in the ice water for longer. People using a distraction strategy were able to keep their hand in the ice water for longer. The effect of cognitive strategy depended on the coping style of the participant. Those with an avoiding coping style kept their hand in the ice water longer when using a distraction strategy, but those with a monitoring coping style kept their hand in the ice water longer when using a sensation-monitoring strategy. 2.5 points A five-way ANOVA has: five dependent variables and two independent variables. one dependent variable and five independent variables. one dependent variable and four independent variables. five dependent variables and five independent variables. 2.5 points The F ratio is calculated by: dividing a measure of within-groups variability by a measure of between-groups variability. averaging the results from the t tests for all possible two-group comparisons. dividing a measure of between-groups variability by a measure of within-groups variability. initially squaring all the scores. 2.5 points According to Cohen’s conventions, an R2 of 0.19 is considered to be a(n) ________ effect size. small medium large erroneous 2.5 points Given a scale dependent variable and a nominal independent variable with three or more levels, we could use a(n) ________ to analyze the data. PRE test z test t test ANOVA 2.5 points A researcher wants to statistically test whether gender affects math test scores. Which test should the researcher use? one-way ANOVA two-way ANOVA three-way ANOVA within-groups ANOVA 2.5 points In a two-way ANOVA, the researcher makes decisions regarding ________ null hypotheses. three separate two separate three interdependent two interdependent 2.5 points A researcher wants to examine people’s preference for pets by having 10 people act as “foster owners” for four different types of family pets: dogs, cats, birds, and fish. The participants will foster each type of pet for one week, and a scale measure will be used to assess preference. What research design should be used? one-way between-groups ANOVA correlation one-way within-groups ANOVA paired-samples t tests 2.5 points The F ratio is a ratio of: two (or more) sample means. two variances. sample means divided by sample variances. two sum-of-squares estimates. 2.5 points A post-hoc test is warranted when: the F is significant and there are more than two groups. we fail to reject the null hypothesis in an ANOVA. we reject the null hypothesis when performing an independent-groups t test. we have an a priori prediction about which group means will differ. 2.5 points A hypothesis test with two nominal independent variables and a scale dependent variable is a: one-way ANOVA. two-way ANOVA. two-groups t test. two-groups z test. 2.5 points A within-groups ANOVA is used when we have ________ independent variable(s) with ________ levels. 1; more than 2 2; more than 2 1; less than 2 2; less than 2 2.5 points Which degrees of freedom value is unique to the one-way within-groups ANOVA? between-groups subjects within-groups total 2.5 points The Bonferroni, Scheffé, and Tukey are all examples of: hypothesis tests. post-hoc tests. effect size statistics. confidence intervals. 2.5 points In Zinman and Zitzewitz’s (2009) research on snowfall reports, they found the following interaction: the amount of snowfall reported by resorts was always exaggerated, but that phenomenon was even greater on the weekends. weekday snow reports were less interesting to skiers than weekend reports. snowfall reports were more common during weekends than weekdays, but this was even more true when there was fresh snow. snowfall reports were exaggerated, and this was more pronounced for the weather reports provided by radio stations compared to resorts. 2.5 points A researcher is interested in whether circadian rhythms influence participants’ performance on different kinds of memory tests. The researcher first classifies participants according to whether each is a morning person or evening person. The researcher then randomly assigns participants to receive either an implicit memory test or an explicit memory test. The researcher next tests everyone at 8 A.M. How many cells does this study have? 2 4 6 8 2.5 points The z, t, and F calculations have something in common: the numerator of the test statistic: contains a measure of difference among groups. contains a measure of sample variability. is a squared number. represents what would be expected to happen by chance. 2.5 points The assumptions for all ANOVAs are the same and include all of the following EXCEPT: random selection of participants population is normally distributed population variances are equal participants are all different across conditions 2.5 points ________ is the proportion of variance in the dependent variable that is accounted for by the independent variable. t Cohen’s d R2 z 2.5 points According to Cohen’s conventions, an effect size of 0.019 for a one-way within-groups ANOVA is considered to be: small. medium. medium-to-large. large. 2.5 points Forys and Dahlquist (2007) investigated the effects of coping style and cognitive strategy on dealing with pain. Participants were first classified as having a monitoring or avoiding coping style. Participants were then randomly assigned to one of two cognitive strategy conditions, distraction or sensation monitoring. Participants were next instructed to use the cognitive strategy while submerging their hand in ice water. The researchers measured pain tolerance as the number of seconds participants were able to keep their hand in the ice water. How would you label the ANOVA used to analyze this data? 4 × 2 between-groups ANOVA 4 × 2 within-groups ANOVA 2 × 2 between-groups ANOVA 2 × 2 within-groups ANOVA 2.5 points Identify the correct formula for degrees of freedom between-groups: Ngroups – 1 n – 1 Ntotal – 1 n – 2 2.5 points A researcher is interested in whether circadian rhythms influence participants’ performance on different kinds of memory tests. The researcher first classifies participants according to whether each is a morning person or an evening person. The researcher then randomly assigns participants to receive either an implicit memory test or an explicit memory test. The researcher then tests everyone at 8 A.M. How would you label the ANOVA used to analyze these data? 4 × 2 between-groups ANOVA 4 × 2 within-groups ANOVA 2 × 2 between-groups ANOVA 2 × 2 within-groups ANOVA 2.5 points A measure of the differences among group means is: the z score. between-groups variance. within-groups variance. the proportionate reduction in error. 2.5 points An interaction occurs when: the dependent variable does not depend on any of the independent variables. two independent variables both influence the dependent variable. the effects of one independent variable depend on the level of the other independent variable. a single independent variable changes the dependent variable, disregarding all other variables in the study. 2.5 points F is obtained by dividing ________ by ________. SSbetween; dfbetween MSbetween; MSwithin dfbetween; SSbetween SSbetween; SSwithin 2.5 points In addition to assessing whether each independent variable has an effect on the dependent variable, a factorial ANOVA also allows you to: use multiple dependent measures in a single analysis. control for a third variable that might be related to the dependent measure, prior to investigating the independent variable of interest. determine whether the effects of one factor depend on the other factor. partition out the variability due to individual differences and the variability due to measurement error. 2.5 points Heteroscedastic populations are those that: have the same variance. have homogeneity of means. share common means. have different variances. 2.5 points According to Cohen’s conventions, an effect size of 0.29 for a one-way within-groups ANOVA is considered to be: small. medium. medium-to-large. large. 2.5 points An effect size of 0.015 for a two-way ANOVA is considered to be: small. medium. large. an error. 2.5 points If you calculate an F statistic and find that it is negative, then you know that: the within-groups variance exceeds the between-groups variance. the difference among the group means is greater than what would have occurred by chance. you have made a calculation error. the difference among the group means is less than what would have occurred by chance. 2.5 points A boarding school (where students live and go to school) wants to find out if students’ scores on a Happiness Rating Scale change over the course of their first year. To this end, they administer the rating scale to students during the first week, and again at the end of the school year. Which type of t-test should the school staff use to test whether there is a significant change in happiness ratings? t-test for independent means one-sample (single sample) t-test t-test for dependent means a combination of all 3. 2.5 points If the results of a two-tailed t-test were to be presented in a research article, and there were 25 participants, what is the appropriate number in parentheses after the t? t(25) t(1) t(2) t(24) 2.5 points A community psychologist observes that children in a certain school tend to score lower on standardized math tests than students at other schools in the district. He knows that the mean scores of children in the district as a whole is 110. Which type of t-test should he use to determine whether the scores of the children in the school differ significantly from the scores in the school district overall? t-test for independent means one-sample (single sample) t-test t-test for dependent means none of the above 2.5 points A psychologist publishes a paper based on a study and states that the results are significant at the .05 level. Based on this information, which of the following could be the p value of the results of the study? .045 .4 .104 .06 2.5 points A social psychologist wants to test whether introverts and extroverts have different numbers of friends on a social networking site. She administers a personality test and, based on the results, divides the participants into 2 groups, Introverts and Extroverts. She then surveys the groups to find out how many friends they have recorded on the social networking site. Which type of t-test should she use to analyze the results? t-test for independent means one-sample (single sample) t-test t-test for dependent means It doesn’t matter, any of them should work.