. Author manuscript; available in PMC: 2016 Jan 5.

Published in final edited form as: Psychol Addict Behav. 2015 Jun 22;29(4):1031–1040. doi: 10.1037/adb0000091

Table 2.

Bias and Uncertainty of Regression Coefficients for Different Numbers of Raters.

Scenario	No. of Raters per Session	Coefficient Estimates			No. of Duplicate Ratings
Scenario	No. of Raters per Session	ICC = 0.8 M (SD)	ICC = 0.6 M (SD)	ICC = 0.4 M (SD)	No. of Duplicate Ratings
1	1	0.40 (0.026)	0.29 (0.034)	0.19 (0.039)	0
2	2	0.45 (0.022)	0.37 (0.029)	0.28 (0.034)	100
3	3	0.46 (0.019)	0.41 (0.024)	0.34 (0.029)	200
4	4	0.47 (0.016)	0.43 (0.022)	0.37 (0.028)	300
5	8	0.48 (0.013)	0.46 (0.016)	0.42 (0.021)	700
6	1–3	0.43 (0.023)	0.39 (0.033)	0.24 (0.036)	60

Note. All models were fit using weighted negative binomial regression.