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assignment 5 Chapter 7 1) To what extent does superstition influence performance? Damisch, Stoberock, and Mussweiler (2010) reported that being assigned a lucky golf ball can improve golf performance. This study was then closely replicated in two separate experiments by Calin-Jageman and Caldwell (2014). For this question, use the Superstition_Golf dataset, which contains the data and descriptions for the second registered replication conducted by Calin-Jageman and Caldwell (2014). a. Make a figure of how participants assigned to the lucky and control conditions differed in terms of golf scores. Obtain the 95% CI for the difference (data two tab in ESCI will do all this for you). The 95% CI for the difference between the mean lucky and control conditions is between -0.897 and 0.688. b. Write an APA-style results paragraph summarizing this finding. Please refer to the writing example of independent samples t-test presented in the SPSS survival manual. We ran an independent sample t-test to analyze how lucky (M=4.02, SD=2.20) and control (M= 4.12, SD=2.01) conditions differed in terms of golf scores. We fail to reject the null hypothesis and cannot conclude a difference between the mean lucky and c control conditions (t (109)= -.25, p>.05). 2). When an experimental manipulation produces very weak effects, there are two possibilities: 1) the independent variable does not substantially influence the dependent variable or 2) the manipulation itself was not effective or strong enough. In this case, the results of Calin-Jageman & Caldwell could occur 1) if superstition does not strongly influence golf performance or 2) if participants simply did not believe in the superstition manipulation. To help determine which possibility is correct, Calin-Jageman & Caldwell asked participants to report the degree to which they actually believed in a lucky golf ball (1-5 scale). This is known as a manipulation check, because it checks to see how effective the manipulation was. Participants were asked about their feelings of luck in two different ways and the Felt_Lucky_Avg column in the Superstition_Golf dataset contains the average of each participant’s response. c. If the manipulation of luck was effective, how should the control and lucky groups differ on this measure? d. Make a figure and obtain a 95% CI for the difference in feeling lucky between the control and lucky groups. e. Interpret the result: to what extent did getting a lucky golf ball succeed in making participants feel luckier? f. If you were using the NHST approach, would this be a statistically significant result? Chapter 8 The makers of Neuro-aid soft drinks claim their drink improves intelligence. Does it really? To find out, 30 participants drank Neuro-aid one day and a sugar-water drink on another (counterbalanced order). 30 minutes after each drink consumption, participants took a Stanford-Binet IQ test (normally to have a mean of 100, SD of 15). Compared to sugar-water, can Neuro-aid soft drinks significantly improve participants’ intelligence? Please use the Neuroaid_memory dataset to do the paired t-test in ESCI software. Answer the research question by writing up results in APA format based on the writing example of paired t-test presented in the SPSS survival manual. Neuro-Aid sugar water Difference = Neuro aid - sugar water 101 99 2 100 96 4 93 102 -9 118 116 2 79 81 -2 106 102 4 100 96 4 114 118 -4 98 101 -3 66 70 -4 101 99 2 89 85 4 104 99 5 89 91 -2 100 101 -1 118 112 6 113 117 -4 61 66 -5 103 101 2 104 101 3 92 89 3 98 95 3 128 130 -2 108 107 1 88 81 7 98 96 2 119 120 -1 97 96 1 108 114 -6 63 57 6 Average 98.533 97.933 0.6 St. Dev. 15.874 16.176 3.988 n 30 30 30 From the sample data, it is found that the corresponding sample means are: Also, the provided sample standard deviations are: s1 =15.874 and s2 =16.176 and the sample size is n = 30. For the score differences we have (1) Null and Alternative Hypotheses The following null and alternative hypotheses need to be tested: Ho: μD = 0 Ha: μD > 0 This corresponds to a right-tailed test, for which a t-test for two paired samples be used. (2) Rejection Region Based on the information provided, the significance level is α=0.05, and the degrees of freedom are df = 29. it is found that the critical value for this right-tailed test is tc =1.699, for α=0.05 and df=29. The rejection region for this right-tailed test is R=t:t>1.699. (3) Test Statistics The t-statistic is computed as shown in the following formula: (4) Decision about the null hypothesis Since it is observed that t=0.824≤tc =1.699, it is then concluded that the null hypothesis is not rejected. Using the P-value approach: The p-value is p=0.2083, and since p=0.2083≥0.05, it is concluded that the null hypothesis is not rejected. (5) Conclusion It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the population mean μ1 is greater than μ2 , at the 0.05 significance level. Confidence Interval The 95% confidence interval is −0.889<μd><2.089. neuroaid does not significantly improve iq at 5%. neuroaid="" does="" not="" significantly="" improve="" iq="" at="">