Unit 11: Analysis of Variance and Prediction Techniques - Practice Quiz

1 What is the main purpose of analysis of variance (ANOVA)?

2 In a one-way ANOVA, what does the null hypothesis usually state?

3 Which test statistic is commonly used in ANOVA?

4 If an ANOVA result has , what is the usual conclusion at the 5% significance level?

5 What does reliability refer to in research measurement?

6 Which type of reliability is assessed by giving the same test to the same participants at two different times?

7 Which statistic is commonly used to assess the internal consistency of a multi-item scale?

8 What does inter-rater reliability measure?

9 What does validity indicate about a research instrument?

10 Which type of validity examines whether an instrument adequately covers all aspects of a topic?

11 Which type of validity examines whether a measure behaves according to the theory of its underlying concept?

12 Criterion validity is assessed by comparing a measure with what?

13 How many predictor variables are used in a simple bivariate regression model?

14 In the bivariate regression equation , what does represent?

15 In the equation , which variable is the dependent variable?

16 What does a positive regression slope indicate?

17 What distinguishes multiple regression from bivariate regression?

18 In multiple regression, what does represent?

19 What is the dependent variable in a multiple regression model?

20 What is multicollinearity in multiple regression?

21 A researcher compares mean test scores across four teaching methods using one-way ANOVA. The analysis gives with . What is the most appropriate conclusion?

22 In a one-way ANOVA, the between-group mean square is and the within-group mean square is . What is the calculated statistic?

23 A one-way ANOVA finds a significant difference among five group means. Which procedure is most suitable for determining which pairs of means differ while controlling the familywise Type I error rate?

24 Three independent groups have strongly unequal variances and noticeably different sample sizes. Which approach is most appropriate for comparing their means?

25 A 20-item attitude scale has Cronbach's alpha of . After removing one poorly correlated item, alpha rises to . What does this result most directly suggest?

26 A researcher administers the same anxiety questionnaire to the same participants twice, two weeks apart, and correlates the two sets of scores. Which type of reliability is being assessed?

27 A test has a standard deviation of and a reliability coefficient of . Using , what is its standard error of measurement?

28 Two trained observers independently classify classroom behavior into the same set of categories. Which statistic is most appropriate for assessing agreement beyond chance?

29 Experts review a new research-methods examination to determine whether its questions adequately represent all areas in the course syllabus. Which form of validity is primarily being evaluated?

30 Scores from a university entrance test are correlated with students' grade point averages obtained at the end of their first year. Which type of validity does this evidence support?

31 A new depression scale correlates strongly with an established depression inventory but weakly with a measure of mathematical ability. What does this pattern support?

32 A questionnaire produces highly consistent scores, but it systematically measures social confidence instead of the intended construct of self-esteem. Which statement best describes the questionnaire?

33 A regression model predicting examination score from study time is , where is the number of study hours. What score is predicted for a student who studies for hours?

34 In the model , where is daily screen time in hours and is a concentration score, how should the slope be interpreted?

35 The correlation between two variables is . In a bivariate linear regression with an intercept, what proportion of variance in the outcome is explained by the predictor?

36 For one participant, a regression model predicts a score of , while the observed score is . Using , what is the residual?

37 A multiple regression model is , where is study hours and is absence days. What is the predicted outcome for and ?

38 In a regression predicting salary from education and work experience, the coefficient for education is when experience is included in the model. How should this coefficient be interpreted?

39 A regression model has and adjusted after several weak predictors are added. What does the difference most reasonably indicate?

40 In a multiple regression model, two predictors have variance inflation factors above , and their estimated coefficients change greatly when either predictor is removed. What is the most likely problem?

41 A one-way ANOVA compares three groups, each containing five observations. The group means are , , and , and the within-group sum of squares is . What is the resulting statistic?

42 In a one-way ANOVA, group sizes are highly unequal and the smallest group has the largest population variance. Assuming normal observations, which conclusion is most appropriate?

43 A repeated-measures factor has four levels, and its uncorrected ANOVA has degrees of freedom . Mauchly's test indicates violated sphericity, with Greenhouse–Geisser estimate . Which correction is applied?

44 In a balanced factorial study, the cell means are and for across and , and and for across the same levels. What pattern of effects is implied?

45 An eight-item standardized scale has an average inter-item correlation of . What is its standardized Cronbach's alpha?

46 A test has reliability . If its length is increased by a factor of using items parallel to the original items, what reliability is predicted by the Spearman–Brown formula?

47 Two measures correlate at . Their reliabilities are and . Under classical test theory, what is the estimated correlation between their error-free true scores?

48 A scale has Cronbach's alpha of but test–retest reliability of . Which interpretation best reconciles these results?

49 Which correlation pattern provides the strongest evidence of convergent and discriminant validity in a multitrait–multimethod matrix?

50 Twelve experts evaluate whether an item is essential, and ten classify it as essential. Using Lawshe's content validity ratio, what is the item's ?

51 A reduced criterion-prediction model has . Adding two focal predictors produces . With and five predictors in the full model, what is the partial statistic for the added predictors?

52 Researchers wish to compare latent construct means across two cultural groups. Which level of measurement invariance is ordinarily required before interpreting the latent mean difference?

53 For variables and , , , , , and . What value of is predicted when ?

54 Given , , and , the slope from regressing on is . What is the slope from separately regressing on ?

55 At , why is a prediction interval for a new individual response wider than a confidence interval for the mean response?

56 A new observation is added far from but lies almost exactly on the existing fitted regression line. What is its most likely effect?

57 Predictor has a near-zero bivariate correlation with outcome , yet its regression coefficient becomes large and significant after predictor is included. Which explanation is most plausible?

58 A predictor has a variance inflation factor of . Relative to an otherwise comparable orthogonal design, by what factor is its coefficient's standard error inflated?

59 A regression model has , four predictors, and . What is the adjusted coefficient of determination?

60 Consider the fitted model . At what value of is the conditional effect of on equal to zero?