The paper "How Happy Was I, Anyway? A Retrospective Impact Bias" (Social Cognition (2003): 421-446) reported on a experiment designed to as the extent to which people rationalize poor performance. In this study, 246 college undergraduates were assigned at random to one of two groups a negative feedback group or a positive feedback group. Each participant took a test in which they were asked to guess the emotions displayed in photographs of faces At the end of the test, those in the negative feedback group were told that they had correctly answered 21 of the 40 items and were assigned a "grade" of D. Those in the positive feedback group were told that they had answered 35 out of 40 correctly and were assigned an A grade.

 

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After a brief times, participants were anked to anewer two weta of questione. One set of questione aaked about the validity of the test and the other set of questions mked about the importance of being shin to mad faces Then researchers hypothesized that those in the negative feedback group would tend to rationalie their poor perfoemance by rating both the validity of the test and the importance of being a good face reader lower than thoe in the positive foedhack group. Face Rending Importance Rating Standard Devlation 1.00 Tet validity Rating Sample Size 123 Standard Group Mean Deviation Mean Negative feedback Positive feedback 5.51 .79 5.36 123 6.95 1.09 6.62 1.19 (a) [3 points Is there convincing evidence that those in the negative feedback group would also not rate the importance of being able to read faces as highly those in the positive group? Use a signicficance level of 06, round your test statistie to the appropriate amount of decimal places to ue the correct chart, nd round everything else to 4 decimal places using the seven-step process learned in class 1. Describe what the population characteristio are meuring H.: 3. Significance level a= 2 Ho: 4. Amumptions: A. B. t 5. Which test statistic should we use for this hypothesis test? Calculate the test statistic 6. Calculate degrees of freedom (if needed): P.value: 7. Conclusion: (b) [2 points) Construct a 90% confidence interval for the difference in mean scores of the face reading importance rating between the negative feedback and positive feedback groupe. (e) [1 point] Write a conclusion sentence stating what the confidence interval meana. (d) [1 point (bonus) Is zero included in the confidence interval? What does this imply about the difference in the means? After a brief times, participants were anked to anewer two weta of questione. One set of questione aaked about the validity of the test and the other set of questions mked about the importance of being shin to mad faces Then researchers hypothesized that those in the negative feedback group would tend to rationalie their poor perfoemance by rating both the validity of the test and the importance of being a good face reader lower than thoe in the positive foedhack group. Face Rending Importance Rating Standard Devlation 1.00 Tet validity Rating Sample Size 123 Standard Group Mean Deviation Mean Negative feedback Positive feedback 5.51 .79 5.36 123 6.95 1.09 6.62 1.19 (a) [3 points Is there convincing evidence that those in the negative feedback group would also not rate the importance of being able to read faces as highly those in the positive group? Use a signicficance level of 06, round your test statistie to the appropriate amount of decimal places to ue the correct chart, nd round everything else to 4 decimal places using the seven-step process learned in class 1. Describe what the population characteristio are meuring H.: 3. Significance level a= 2 Ho: 4. Amumptions: A. B. t 5. Which test statistic should we use for this hypothesis test? Calculate the test statistic 6. Calculate degrees of freedom (if needed): P.value: 7. Conclusion: (b) [2 points) Construct a 90% confidence interval for the difference in mean scores of the face reading importance rating between the negative feedback and positive feedback groupe. (e) [1 point] Write a conclusion sentence stating what the confidence interval meana. (d) [1 point (bonus) Is zero included in the confidence interval? What does this imply about the difference in the means?