Exam 3 - 1 ID# Exam 3 PS 217, Spring 2008 (You must use your official student ID) As always, the Skidmore Honor Code is in effect. You’ll attest to your adherence to the code at the end of the exam. Read each question carefully and answer it completely, showing all your work (so that you can receive partial credit). Have a peaceful and relaxing summer. 1. [Sprinthall] Assume that a researcher is interested in whether or not there is a relationship between a politician’s physical attractiveness and her or his years in office. The researcher takes a random sample of eight members of Congress from throughout the country and ranks them on attractiveness (1 = “low attractiveness” and 8 = “high attractiveness”). These rankings are paired with the number of years each has served in the House of Representatives. Use these data to provide an answer to the question. [15 pts] Member Attractiveness Years Served A 1 6 B 2 8 C 3 12 D 4 14 E 5 12 F 6 20 G 7 20 H 8 24Exam 3 - 2 2a. In a study of early ability to detect a fear-relevant stimulus (a snake), LoBue and DeLoache (2008) presented 3-year-old children and adults (Age: 3-year old vs. adult) a series of 3x3 matrices of pictures. The subject’s task was to point out a target by touching one of the nine pictures on a touch-screen (Target: either a snake among eight non-snake distractors or a non-snake animal, such as a caterpillar, among eight snake distractors). Thus, we can think of this study as a 2x2 independent groups design. Below is a partially completed source table that is consistent with their results (Experiment 3). Complete the source table and interpret the results as completely as you can. [15 pts] Dependent Variable:Response Latency Source Type III Sum of Squares df Mean Square F Sig. Partial Eta Squared Observed Powerb Age 72.030 .000 .700 1.000 Target 10.830 .000 .259 .970 Age * Target 3.630 .028 .105 .604 Error 30.920 Corrected Total 117.410Exam 3 - 3 2 (continued). [15 pts.] 2b. Looking at the SPSS output, what are the effect sizes for the three Fs? How are the effect sizes related to the F-ratios and to the power estimates? 2c. The F-ratio for the interaction may be significant, but it is smaller than the F-ratios for the main effects. Why? How might you increase the F-ratio for the interaction? 2d. Suppose that you re-computed the ANOVA as a single-factor analysis on the Age factor. What would that source table look like? SOURCE SS df MS F 2e. Test the null hypothesis that for the adults, H0: µ = 2.0. That is, using the information in the Descriptive Statistics table for the problem, compute the appropriate statistic to test the hypothesis that the mean for the sample of adults was drawn from a population with µ = 2.0.Exam 3 - 4 3. In the first lab in PS 306 this semester (something to look forward to), we collected a number of different academic measures. Below are the results from a correlation analysis of two different SAT scores (Math and Verbal/Critical Reading). First of all, tell me what you could conclude from these results. Then, given an SAT-V score of 600, what SAT-M score would you predict using the regression equation? Given the observed correlation, if a person studied only for the SAT-V and raised her or his SAT-V score, would you expect that person’s SAT-M score to increase as well? What would you propose as the most likely source of the observed relationship? [10 pts]Exam 3 - 5 4. A variety of research results suggest that visual images interfere with visual perception. In one study, Segal and Fusella (1970) had seven subjects watch a screen, looking for occasional brief presentations of a small blue arrow. On some trials, the subjects were also asked to form a mental image (e.g., imagine a volcano). The results show that subjects made more errors on trials on which they were forming images compared to trials on which they were not forming images. Data similar to Segal and Fusella are as seen below. Analyze the data to see if the trials differed, interpreting the results as completely as possible. [15 pts] Errors With Image Errors Without Image 13 4 9 2 12 10 7 8 10 6 8 6 9 4 Sum 68 40 Mean 9.71 5.71 SS 27.43 43.42Exam 3 - 6 5. A researcher is interested in investigating the impact of the drug magnesium pemoline (MgPe) on retention of learned material. A group of 16 people is randomly selected from the population of students at a large university. The people are then randomly assigned to one of four conditions: Placebo, 10cc of MgPe, 20cc of MgPe, or 30cc of MgPe. All the people are given the same material to read and four hours later are tested for retention (higher scores indicate greater retention). Analyze the data as completely as you can, including very clear advice about what to do next. [20 pts] Placebo 10cc MgPe 20cc MgPe 30cc MgPe 8 10 11 10 6 7 6 8 7 8 8 7 5 6 9 9 Sum 26 31 34 34 ΣX2 174 249 302 294 SS 5 8.75 13 5Exam 3 - 7 6. Researchers are interested in a phenomenon called hindsight bias. When you hear people talk about being a Monday Morning Quarterback, they’re referring to this hindsight bias. Thus, knowing the results of professional football games on Sunday leads people to be more confident that they would have been able to predict the outcomes before the games (i.e., on Saturday). Psychologists have studied this phenomenon in a number of ways, but one way is through anagram solving (turning scrambled letters into words). That is, we can present some people with anagrams to solve and measure the time (in minutes) to solve the anagrams (the Worksight Condition). For other people, we can present the anagrams and the solutions simultaneously. Their task is to estimate the time they think it would take someone to solve the anagram (the Hindsight Condition). Thus, to the extent that hindsight bias is present, the estimated times in the Hindsight Condition will be less than the actual solution times in the Worksight Condition. In addition to this factor, we might also examine the extent to which anagram length has an impact on hindsight bias. Thus, the two independent variables would be: TASK (actually solve anagrams vs. with solution present, estimate time to solve) and LENGTH (anagrams would be 4, 6, or 8 letters long). Complete the analysis below, and interpret the results as completely as you can. [20 pts] Dependent Variable:"Solution" Time