C. Post-Data Analysis 1. Determine and interpret the estimated effect size using Cohen's

d. 2. Determine and interpret the effect size relative to explained variance (r). 3. Determine and interpret the power of the study from a post hoc perspective. 4. Determine and interpret the 95% confidence interval, including its precision and AIPE. 5. Present at least two plausible explanations for the results.

This research study is with respect to an aviation maintenance, repair, and overhaul (MRO) facility, and the objective is to assess the effect a stress management initiative has on reducing employees' stress level. The rationale for the study is grounded in the belief that employee stress could lead to increased feelings of rushing to com- plete a maintenance task, frustration, fatigue, and complacency, all of which could lead to maintenance errors. To implement the study, a researcher pre-assessed em- ployees' stress level using the Stress subscale of Fogarty's (2005) Maintenance Envi- ronment Survey. This 9-item subscale assesses participants' perceived feelings and consequences about their stress and what contributes to it. A sample item is, "The demands of my work interfere with my home and family life." Items are scored using a traditional 5-point Likert scale ranging from 1 = Strongly Disagree to 5 = Strongly Agree. Thus, overall scores could range from 9 to 45, with higher aggregate scores reflecting higher levels of stress. Following the pre-assessment, employees en- gaged in various stress reduction activities for 1 month. These included a 30-minute extended lunch break each day, access to free onsite mental health counseling, a 1-hour after-work social event every Friday afternoon, and a 30-minute stress- reduction strategies workshop that was scheduled at various times each day to accommodate employees' different schedules. At the end of the study period, em- ployees were post-assessed using the same instrument. The corresponding data are located in the file Ch_11 Exercises Part B Data. Your assignment is to import this data set into your statistical software program and analyze the data using a repeated- measures t test.