d. When one predictor is highly correlated with the dependent variable 2. When do we speak of homogeneity in analysis of variance (ANOVA)? a. When all independent variables have the same variance | b. When the dependent variable is normally distributed | c. When the variance of the dependent variable is the same in all groups | d. When all groups have the same size |
3. A consumer psychologist performs a between-subjects ANOVA to study the effect of personality type (introvert, extrovert, ambivert) and gender (female, male) on consumption. When do we speak of an interaction between personality type and gender? a. If all six groups have the same size | b. If within each personality type men buy more than women | c. If the effect of gender is the same for each personality type | d. If the effect of personality type is different for men than for women 4. Suppose we perform an analysis of covariance (ANCOVA) with one factor and one covariate. It turns out that the groups do not differ on the covariate. Furthermore, the within-groups regression coefficient bw is significantly smaller than 0. What goal would performing an ANCOVA have in this case, compared to an ANOVA without the covariate? a. No reduction of error variance and no removal of systematic bias | b. Removal of systematic bias only | c. Reduction of error variance only | d. Both reduction of error variance and removal of systematic bias 5. Why should one use covariates sparingly in ANCOVA? a. The statistical power of the F test decreases if the covariate hardly correlates with the dependent variable | b. The F test becomes less robust to violations of homoscedasticity if too many covariates are used | c. The F value increases if the covariate hardly correlates with the dependent variable | d. The explained variance may drop if too many covariates are used 6. An educational psychologist performs a logistic regression analysis (LRA) to investigate if passing an exam can be predicted from the number of plenary lectures that were attended. The odds ratio of the predictor (number of attended lectures) equals 5. What does this mean? a. For every exam score the probability of passing is five times as large as the probability of failing | b. For every exam score the odds of passing are five times as large as the odds of failing | c. The probability of passing becomes five times as large if you attend one more lecture | d. The odds of passing become five times as large if you attend one more lecture 7. In a study with 80 subjects (40 females, 40 males) the odds that a subject seeks psychological help are 0.5. What does this mean? a. The probability that a subject seeks help is twice as large as the probability that a subject does not seek help | b. The probability that a subject seeks help is the same for females and males | c. The probability that a subject does not seek help is twice as large as the probability that a subject seeks help | d. The probability that a subject seeks help is equal to the the probability that a subject does not seek help 8. What is Box's M used for in MANOVA? a. To test the assumption of homogeneity of the variance-covariance matrices b. To test whether the groups differ significantly from each other c. To test the assumption of independent errors d. To test the significance of the discriminant functions 9. What is the maximum number of discriminant function variates for a MANOVA with three groups and four variables? a.1 | b.2 | c.3 | d.4 10. Evaluate the following two statements on the role of contrasts in the multivariate approach to repeated measures ANOVA with p variables. 1) The multivariate tests are based on a set of (p-1) linear independent contrasts
2) The contrasts allow testing specific hypotheses about mean differences between groups a. Both statements are correct | b.Statement 1 is correct, statement 2 is incorrect | c.Statement 1 is incorrect, statement 2 is correct | d.Both statements are incorrect 11. Do-it-yourself 1. An insurance psychologist, who specialises in behavioural aspects of DIY-related accidents, discovered that in many of the investigated incidents involving serious injury, the DIYer concerned had spent little or no time reading the instruction manual for the equipment used. (``Gosh, was there a blade guard on that circular saw? And children really shouldn't play with it? No, I didn't know that!''). Nearly everyone had glanced at the instruction manual, but only a few had studied it carefully. The psychologist wonders what factors determine how much time the DIYer spends on studying the manual: type of equipment, gender of the DIYer, number of years of DIY experience? Working in conjunction with a DIY store, she asks 400 people who bought a circular saw, pneumatic hammer or power drill to fill in a questionnaire a month after the purchase. This questionnaire asks about the type of equipment (circular saw, hammer or power drill), gender, number of years of DIY experience, and number of minutes spent reading the instruction manual for the purchased equipment. Which of the following methods is the most appropriate to answer this question? a. multiple regression analysis (MRA) | b.analysis of variance (ANOVA) | c.analysis of covariance (ANCOVA) | d.mediation analysis 12. Do-it-yourself 2. A positive psychologist thinks that introverted people get more enjoyment from DIY than less introverted people, because while doing DIY jobs they are more in a state of ``flow''. To investigate this, she brings 300 experienced DIYers into the lab, where each of them does the same job with 38 electrodes attached to his/her head. Before doing the job, they are all measured in terms of introversion level; while working on the job, the number of seconds in ``flow'' is measured on the basis of flow-related brain patterns; and after completion of the job, everyone is asked to rate on a 9-point scale how much they enjoyed doing the job. Which of the following methods is the most appropriate to investigate this hypothesis? a. analysis of variance (ANOVA) | b.analysis of covariance (ANCOVA) | c.repeated measures ANOVA (RMA) d.mediation analysis 13. Do-it-yourself 3. A manager of a roofing company wonders about the extent to which the time taken to do a job is determined by the following factors: the size of the roof, the number of roofers working on the job, the number of years of experience of the roofers? To answer this question, she extracts some data from the company records on all the jobs done over the last five years: roof area (in square meters), number of roofers working on the job, mean number of years of experience of those roofers, and number of hours between the beginning and end of the job. Which of the following methods is the most appropriate to answer this research question? a. multiple regression analysis (MRA) | b.analysis of variance (ANOVA) | c.analysis of covariance (ANCOVA) |
d.multivariate analysis of variance (MANOVA) 14. The ball is round. When a soccer match ends in a draw, it sometimes has to be decided with a penalty shoot-out. A former coach of the Dutch national team says there is little point in special training for penalties, but not everyone agrees with this view. A research group has the following hypothesis: the greater the general productivity of a team and the more training for penalties, the greater the probability of winning a penalty shoot-out. They decide to investigate this by measuring the following aspects of all European Championship matches between 1952 and the present which were decided on penalties, for each team playing at home. - Training for penalties: for how many minutes had the players practiced penalties during training in the previous week?
- General productivity: how many goals per match had been scored on average in the previous five matches?
- Result: did the team win or lose the penalty shoot-out?
Which of the following methods is the most appropriate to investigate this hypothesis? a.multiple regression analysis (MRA) b.analysis of variance (ANOVA) c.analysis of covariance (ANCOVA) d.logistic regression analysis (LRA) 15. Charisma. A political analyst wonders which party leader has the most charisma in the view of the Dutch electorate. To find out, he asks a large, representative sample of voters to rate the charisma of each of the leaders of the five largest parties on an 11-point scale, from 0 = no charisma at all, to 10 = fantastic charisma. Which of the following methods is the most appropriate to compare the charisma of the five party leaders? a. multiple regression analysis (MRA) | b.analysis of covariance (ANCOVA) | c.multivariate analysis of variance (MANOVA) d.repeated measures ANOVA (RMA) Answers: 1 -a 2 - c 3 -d 4- c 5- a 6 - c 7- c 8 - a 9 - b 10 - a 11- c 12 - d 13 - a 14 - d 15 - d |
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