Hypothesis Testing, Correlation & Regression in Psychological Research, Exams of Psychology

Download Hypothesis Testing, Correlation & Regression in Psychological Research and more Exams Psychology in PDF only on Docsity! PSYC 201 - Psychological Research I Assignment # ____ DUE: _________________________ Hypothesis Testing, Correlation & Regression Hypothesis Testing… Put the correct answer in the blank to the left of each question. ________ 1. For a Pearson r of -0.60, the coefficient of determination equals ______. ________ 2. For a Pearson r of 0.90, _______% of the variance on one variable is explained by the other variable. ________ 3. True/False: For making predictions from one variable to another, a Pearson r of -0.78 is better than a Pearson r of 0.52. ________ 4. True/False: A Pearson r value of 0.00 indicates that there is no relationship between the two variables. ________ 5. True/False: A Pearson’s r is best used to describe curvilinear relationships. ________ 6. True/False: The general purpose of linear regression is to develop a straight-line equation that permits the prediction of scores for individuals. ________ 7. True/False: If the .05 level is used, there are, on the average, 5 or fewer chances in 100 of making a Type I error. ________ 8. True/False: If the .01 level is used, there are, on the average, 1 of fewer chances in 100 of making a Type II error. ________ 9. True/False: As the probability of making a Type I error is reduced, the probability of making a Type II error is increased. ________ 10. True/False: Significance testing makes it possible to make absolute, definite interpretations of the outcomes of a study. ____________ 11. Reject H0/ Do Not Reject: The observed value of r is 0.62, and the critical value of r is 0.39. ____________ 12. Reject H0/ Do Not Reject: The probability of obtaining the r value you calculated on your data was 0.12. ____________13. Reject H0/ Do Not Reject: When you ran the SPSS analysis on your data, you obtained a sig. value of .000. Was there a significant effect? ____________ 14. Reject H0/ Do Not Reject: The critical value was 2.06, the obtained value for the t-test you ran on your data was 1.93. ____________ 15. Reject H0/ Do Not Reject: The observed value of r is -0.49, and the critical value of r is 0.39. Correlation and Regression For problems 1 and 3 below, do the following: 1. Set up the hypothesis test 2. Analyze the data (calculate the Pearson r Correlation Coefficient) 3. Make your decision (to reject the null hypothesis or not) 4. Create a scatter plot of the data using SPSS; make it conform to APA-style & turn it in 5. Write a brief APA-style results paragraph with your conclusions 1. As the new personnel director of a large company, it is your responsibility to assure merit-based equity in salary levels. In other words, salary level should roughly parallel educational qualifications. However, you have no idea if the current employees are in line with this directive. So you draw a random sample of 15 personnel files (from 15 employees that have been with the company for 5 years) to see if there is a good correlation between salary level and years of education. The data follow: Years: Salary: Years: Salary: 12 22,500 12 22,300 12 17,900 10 14,000 11 16,500 12 13,700 16 29,600 19 54,000 16 34,500 18 34,000 18 42,600 14 25,000 17 45,800 13 21,400 16 24,000 2. Suppose a new employee is hired and the person has had 15 years of education. What would you predict their salary should be (based on the regression equation for the data above)? 3. One measure of the poverty level of a county is the percentage of children who qualify for free lunches at school. A researcher hypothesizes that those counties with a large number of children receiving free lunches (those with more poverty) will also have a larger proportion that do poorly on the SAT college entrance examination. The following are the data from a sample of counties. The data are the % of pupils with free lunch, as well as a composite measure of how well the county’s pupils scored on the SAT (average system SAT): % Pupils Av Sys SAT` % Pupils Av Sys SAT 68 34 69 69 71 15 54 59 56 37 55