1 Prior to conducting an ANCOVA, the researcher conducted assumption testing. The assumption of Normality (Shapiro-Wilks) was conducted on the control group's pretest (p = .004). Was the assumption tenable? Yes No QUESTION 2 Prior to conducting an ANCOVA, the researcher conducted assumption testing. The assumption of homogeneity of variances was tested , Levene's Test, F(2, 432) = .45, p = .08. Was the assumption tenable? Yes No QUESTION 3 Is the statistical correction for nonequivalence among groups likely to be as effective a means of controlling for the covariate as experimental methods of control (such as creating equivalent groups by random assignment)? Yes No QUESTION 4 The primary goal of analysis of covariance (ANCOVA) is to: control for treatment differences to determine if participant characteristics are statistically different. determine differences among treatment groups while controlling for or removing the effects of some participant characteristics. increase the statistical power of experimental designs by increasing the error variance. measure the differences in some participant characteristic after the experiment has been conducted. QUESTION 5 What information is needed to assess whether scores on the covariate X are strongly linearly related to Y (the dependent variable)? Scatter plots Shapiro-Wilks Levene's Test A bar chart QUESTION 6 A quasi experimental study was performed to assess the effects of different types of models for aggressive behavior on spontaneously occurring aggressive behavior in children. A baseline measure of aggressiveness was obtained for each child prior to treatment. Children were non-randomly assigned to the three treatment groups and participants in each group saw a film with a different type of aggressive actor. Group 1 saw an aggressive cartoon animal, participants in Group 2 saw a human female, and participants in Group 3 saw a human male. The assumption of Homogeneity of Slopes was tested, F(2,18) = .349, p = .71. Was the assumption tenable? Yes No QUESTION 7 What is a quantitative measure of some pre-existing participant characteristic (such as body weight, anxiety, motivation, mental ability, or baseline heart rate) that may differ between groups prior to the administration of any interventions or treatments? Covariate Independent Variable Dependent Variable QUESTION 8 A researcher collected data on married couples to see whether counseling helps marital satisfaction. Each married couple filled out a pretest that measured their level of marital satisfaction. The researcher randomly assigned the couples to either a control group or a marital counseling group. At the end of six months the couples filled out a posttest that measured their level of marital satisfaction. What is the best analysis for this study? ANOVA Two-way ANOVA ANCOVA QUESTION 9 An ANCOVA makes the assumption that the slope that relates scores on Y to scores on Xc is equal (homogenous) across the groups compared in the study. The slope that is used to adjust Y outcome scores is essentially the pooled or averaged regression slope to predict Y from Xc, separately at each level of the A treatment factor. If the slope that relates Y to Xc is actually different across levels of the A treatment variable, then it does not make sense to average the slopes together across groups and to use the same slope to make a correction within each group. What is this assumption called? homogeneity of normality homogeneity of correlation homogeneity of regression (slopes) homogeneity of variance QUESTION 10 When reporting the \"adjusted means" of an ANCOVA, you should also report their corresponding: Standard Error Sampling Error Standard Deviation QUESTION 11 Interpret the effect size ( 2) for the ANCOVA: F(2, 57) = 7.9, p = .001, partial 2 = . 43. Large Medium Small QUESTION 12 Generally speaking, statistical control using ANCOVA is as powerful as using experimental control in dealing with confounding participant characteristics. True False QUESTION 13 Which is not a reason for using ANCOVA: to control for some pre-existing characteristic of subjects which may affect scores on the outcome variable. to adjust for nonequivalence of treatment groups in quasi-experimental designs . in place of a well-controlled laboratory experiment that uses random selection and assignment. QUESTION 14 Which would be an example of a valid covariate in an ANCOVA analysis: IQ scores on students measured before implementing different reading comprehension programs. anxiety scores on subjects after implementing drug treatment interventions for depression. motivation level of subjects after implementing a smoking cessation intervention. QUESTION 15 Why is ANCOVA often used in situations that involve nonequivalent control groups? To statistically control for differences in participant characteristics when we assess differences in group means on outcome measures. To study additional variables of interest. To demonstrate how groups were equivalent prior to collecting data