Name:_______________________ Person #: ______________ Recitation Section: __________ PSY207 Problem Set 4, Chapters 12 – 14 Using the space provided, report your answers to each question. Please show ALL your calculations, feel free to do so with additional sheets of paper, and make clear what your final answer is. Please round your answers to two decimal places. 1.) In an effort to improve reading scores, two new methods of reading interventions were tested. With three groups (A: control, B: method 1, C: method 2), we obtain the data below: A B C T = 5 T = 25 T = 30 SS = 12 SS = 20 SS = 14 n = 5 n = 5 n = 5 M = 1 M = 5 M = 6 ΣX2 = 356 N = 15 G = 60 a.) Complete your ANOVA Summary Table. b.) Using an alpha level of .05, what is the Fcrit value and can we conclude that there is a significant difference between treatments? Fcritical = c.) Use the Tukey’s HSD test to determine which of the treatments are significantly different from each other. Use the α = .05 level of significance for all tests. Source SS df MS F Between Treatment Within Treatment TotalName:_______________________ Person #: ______________ Recitation Section: __________ d.) Calculate the proportion of variance account for (η2) η2 = 2.) A researcher has decided to test whether a new drug therapy is effective at reducing anxiety symptoms. She tests four individuals at three different levels of medication and finds the results in the table below. Can we conclude that there is a difference in anxiety levels at different medication levels? Subject Treatment A Treatment B Treatment C P P2/ k G = 48 ΣX2 = 294 k = 3 A 6 2 3 B 5 1 5 C 0 5 10 D 1 8 2 T = 12 ΣxA2 = _____ T = 16 ΣxB2 = _____ T = 20 ΣxC2 = _____ a.) Complete your ANOVA Summary Table. b.) Using an alpha level of .05, what is the Fcrit value and can we conclude that there is a significant difference between treatments? Fcritical = Source SS df MS F Between Treatment Within Treatment Between Subjects Error Total SSPkGNbetween subjects 2 2= _____Name:_______________________ Person #: ______________ Recitation Section: __________ 3.) Use the following data to complete parts a – g. a.) Plot the data using the graph to the right. b.) Does there seem to be a relationship? If so is it… Circle one Positive, Negative, or None c.) Calculate the Pearson correlation coefficient (r). d.) Using an alpha level of .05, report your degrees of freedom (df ) and if your correlation coefficient is significant? e.) What is your coefficient of determination (r 2). r 2 = f.) Find the regression equation for predicting Ŷ from X. g.) Use the regression equation to find Ŷ given the following X values. X Y 1 2 4 7 3 5 2 1 5 14 3 7 X Ŷ 1 4 3 2 5 3Name:_______________________ Person #: ______________ Recitation Section: __________ Points below do not require responses. These are simply conceptual items that you should review for the exam - Be familiar with the logic of ANOVA: what research situation warrants its use? What is the relationship between Total, Between, and Within variances and their role in computing F-ratios - Be familiar with the conceptual rationale behind Multi-factor ANOVA o What are the characteristics of a Multifactor Design?  Factors versus Levels o What is a main effect? Be able to identify it. o What is an interaction? Be able to identify one. - What’s the problem with running a series of t-tests in lieu of an ANOVA? - What information does a Pearson’s correlation coefficient covey? What are its characteristics? - Relationship between correlation, third variables, and causation o When you calculate a “partial correlation,” what are you doing? - What is the coefficient of determination (r2) and what does it