Hi Shan,
It looks like you are interested in looking at the reliability of your scale measures, the reliability of the means of aggregate measures, and the amount of agreement in group measures. The need to demonstrate evidence of agreement in group measures is first determined by your theory; some group measures may not be dependent on agreement. For example, a group measure of climate strength could be the amount of variability around the group mean. Here is a great overview of aggregation issues:
Chan, D. (1998). Functional levels among constructs in the same content domain at different levels of analysis: A typology of composition models. Journal of Applied Psychology, 83, 234-246.
For your group measures that are dependent on agreement, and for the distinction between agreement and reliability, here are a few articles to supplement Victoria's suggestion:
Bliese, P.D. (2000). Within-group agreement, non-indepedence, and reliability: Implications for data aggregation and analysis. In K.J. Klein & S.W.J. Kozlowski (Eds.), Multilevel theory, research, and methods in organizations. San Francisco: Jossey Bass.
Bliese, P. (2013). Multilevel Functions: R Package 'multilevel', Version 2.5.
Biemann, T., Cole, M.S., & Voelpel, S. (2012). Within-Group Agreement: On the Use (and Misuse) of rWG and rWG(J) in Leadership Research and Some Best Practice Guidelines. Leadership Quarterly, 23, 66-80.
Liao, S.C., Hunt, E.A., & Chen, W. (2010). Comparison between inter-rater reliability and inter-rater agreement in performance assessment. ANNALS Academy of Medicine Singapore, 39(8), 613-618.
Wagner, S.M., Rau, C., & Lindemann, E. (2010). Multiple informant methodology: a critical review and recommendations. Sociological Methods & Research, 38(4), 582-618.
Cohen, A., Doveh, E., & Nahum-Shani, I. (2007). Testing agreement for multi-item scales with the indices rWG(J) and AD M(J). Organizational Research Methods, 12(1), 148-164.
Good luck with your research!
Mark
Hi Shan,
You may find this article to be helpful:
LeBreton, J. M., & Senter, J. L. (2007). Answers to 20 questions about interrater reliability and interrater agreement. Organizational Research Methods.
Best,
Victoria
On Thu, Nov 12, 2015 at 10:28 AM, Shan Ran
<fa3074@wayne.edu> wrote:
Dear OB colleagues,
I am working on a multilevel dataset, which contains peer ratings of each other in each team using multi-item scales, as well as group member ratings on team characteristics using multi-item scales. I have several research questions regarding relationships among individual level variables (e.g., personality, performance rated by others). I also have several research questions involving team-level moderators (e.g., team-level task characteristics).
For data aggregation, I will need evidence for peer agreement on each team member's behaviors, team member agreement on team characteristics, and good internal consistency for each multi-item scale. Currently, I run into a question related to this procedure: What is the correct order of computing Cronbach's alpha, computing rwg/ICC, and aggregating data? I have come up with two plausible options, but I am not sure about the appropriateness of each:
1) Using the peer rating data, compute Cronbach's alpha for each scale before computing agreement indices. Is dependency issue a concern since each rater provided multiple sets of ratings for other team members?
2) Compute agreement indices first. After aggregating peer ratings for each individual (given good agreement), compute Cronbach's alpha for each scale using individual level data. Is good internal consistency a requirement for testing rwgj? If I am computing ICCs using scale scores, I will need to demonstrate appropriateness of computing scale scores first.
Each one seems to have its pros and cons. Any advice would be highly appreciated.
Best Regards,
Shan
--
Shan Ran, M.A.
Doctoral Candidate of Industrial and Organizational Psychology
Graduate Consultant at the Research Design and Analysis (RDA) Unit
Wayne State University
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Victoria Prescott Mattingly, MSIndustrial/Organizational Psychology Graduate Student
Department of Psychology
Colorado State University
Fort Collins, CO
Office: 327 Behavioral Sciences Building