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. Author manuscript; available in PMC: 2012 Dec 1.
Published in final edited form as: Psychol Methods. 2011 Oct 31;16(4):373–390. doi: 10.1037/a0025813

Table 5.

Mean and Standard Deviation of the Random Intercept Dispersion Estimate τ^00 as a Function of the Number of Clusters and Cluster Size, Collapsing Over Number of Categories and Category Distribution.

Clusters/Cluster Size Small random effect variance (τ00=0.50) Medium random effect variance (τ00 =1.63) Large random effect variance (τ00=8.15)
Population τ00 = 0.71 Population τ00 = 1.28 Population τ00 = 2.85



Linear – REML Logistic – PQL Logistic – ML Linear – REML Logistic – PQL Logistic – ML Linear – REML Logistic – PQL Logistic – ML
25 Clusters
 5 Members 0.63 (.33) 0.68 (.33) 0.66 (.35) 1.11 (.34) 1.17 (.34) 1.22 (.42) 2.28 (.57) 2.30 (.54) 2.92 (1.41)
 10 Members 0.64 (.21) 0.68 (.22) 0.65 (.23) 1.11 (.25) 1.20 (.26) 1.21 (.28) 2.26 (.50) 2.45 (.49) 2.80 (.62)
 20 Members 0.64 (.15) 0.68 (.16) 0.66 (.16) 1.11 (.22) 1.22 (.22) 1.21 (.23) 2.24 (.47) 2.56 (.45) 2.76 (.53)
50 Clusters
 5 Members 0.64 (.23) 0.65 (.23) 0.67 (.25) 1.12 (.24) 1.14 (.24) 1.26 (.28) 2.26 (.44) 2.21 (.42) 2.87 (.57)
 10 Members 0.65 (.14) 0.67 (.15) 0.68 (.16) 1.11 (.19) 1.18 (.18) 1.25 (.20) 2.45 (.40) 2.40 (.38) 2.83 (.42)
 20 Members 0.65 (.11) 0.68 (.11) 0.68 (.11) 1.11 (.17) 1.21 (.15) 1.25 (.16) 2.23 (.39) 2.53 (.34) 2.81 (.36)
100 Clusters
 5 Members 0.65 (.15) 0.65 (.16) 0.69 (.17) 1.11 (.18) 1.12 (.17) 1.26 (.19) 2.24 (.38) 2.16 (.37) 2.85 (.37)
 10 Members 0.65 (.10) 0.67 (.10) 0.69 (.11) 1.11 (.15) 1.17 (.13) 1.26 (.14) 2.23 (.36) 2.37 (.33) 2.83 (.29)
 20 Members 0.65 (.08) 0.68 (.08) 0.70 (.08) 1.11 (.14) 1.21 (.11) 1.26 (.12) 2.23 (.34) 2.52 (.28) 2.83 (.25)
200 Clusters
 5 Members 0.65 (.11) 0.65 (.11) 0.70 (.12) 1.11 (.14) 1.12 (.13) 1.27 (.13) 2.23 (.34) 2.14 (.34) 2.84 (.26)
 10 Members 0.65 (.08) 0.67 (.07) 0.70 (.08) 1.11 (.13) 1.17 (.10) 1.27 (.10) 2.24 (.33) 2.35 (.30) 2.85 (.20)
 20 Members 0.65 (.07) 0.68 (.05) 0.70 (.05) 1.11 (.12) 1.21 (.08) 1.27 (.08) 2.23 (.32) 2.51 (.25) 2.84 (.18)

Notes. See Table 3 notes.