Week 5 Practice Worksheet PSY/315 Version 6 University of Phoenix Material Week 5 Practice Problems Worksheet Chapter 13 The items below (#1, #2 and #3) are based on the following table. Tension Fatigue Vigor Fatigue .36* Vigor -.31* -.73*** Sleepiness .08 .57** -.49** * p < .05, ** p < .01, *** p < .001 1) The strongest correlation is between __________ and __________. (Give variable names.) 2) The weakest correlation is between __________ and __________. (Give variable names.) 3) The correlation between sleepiness and fatigue is __________ (indicate direction) and __________ (indicate strength). 4) Name the correlation coefficient used to determine the relationship between two ranked or ordinal factors. _____________________________________________. 5) Name the correlation coefficient used to determine the relationship between two interval or radio factors. _____________________________________________. 6) Name the correlation coefficient used to determine the direction and strength of the linear relationship between one factor that is continuous (on an interval or ratio scale of measurement) and another factor that is dichotomous (on a nominal scale of measurement). _____________________________________________. 7) Name the correlation coefficient that is a measure of the direction and strength of the linear relationship of two dichotomous factors on a nominal scale of measurement. __________________________________________________. 8) Make up a scatter diagram with 10 dots for each of the following situations: (a) perfect positive linear correlation, (b) large but not perfect positive linear correlation, (c) small positive linear correlation, (d) large but not perfect negative linear correlation, (e) no correlation, and (f) clear curvilinear correlation. Copyright 2013 by Pearson Education, Inc. All rights reserved. Used with permission. 1 Correlation Study Worksheet PSY/315 Version 6 University of Phoenix Material Correlation Study Worksheet Your research team has been tasked with finding the correlation of the following scenario: Four research participants take a test of manual dexterity (high scores mean better dexterity) and an anxiety test (high scores mean more anxiety). The scores are as follows: Person Dexterity Anxiety 1 2 3 4 1 1 2 4 10 8 4 -2 Describe the process that your research team would go through by completing the following: 1. 2. 3. 4. 5. Make a scatter diagram of the scores. Describe in words the general pattern of correlation, if any. Figure the correlation coefficient. Figure whether the correlation is statistically significant (use the .05 significance level, two-tailed). Explain the logic of what you have done, writing as if you are speaking to someone who has never heard of correlation (but who does understand the mean, standard deviation, Z scores, and hypothesis testing). 6. Give three logically possible directions of causality, indicating for each direction whether it is a reasonable explanation for the correlation in light of the variables involved (and why). References Copyright 2013 by Pearson Education, Inc. All rights reserved. Used with permission. Copyright 2015 by University of Phoenix. All rights reserved. 1