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. Author manuscript; available in PMC: 2014 Aug 25.
Published in final edited form as: Br J Math Stat Psychol. 2013 Feb 25;67(1):94–116. doi: 10.1111/bmsp.12008

Table 2.

Monte Carlo Estimates (Mean Only) at Some Specific Conditions

Standard estimation Mixture estimation

Group Growth factor Parameter Generated Generated Missing Same
Condition 1: Quadratic slope added
G1 Intercept 5.0 5.001 (.081) 5.001 (.081) 5.004 (.081) 5.005 (.081)
Linear slope 0.1 0.089 (.072) 0.089 (.072) 0.089 (.072) 0.089 (.072)
Quad slope 0.02 0.022 (.019) 0.022 (.019) 0.022 (.019) 0.022 (.019)

G2 Intercept 3.0 2.974 (.144) 2.974 (.144) 2.974 (.144) 2.974 (.144)
Linear slope 0.5 0.530 (.130) 0.530 (.130) 0.530 (.130) 0.530 (.130)
Quad slope 0.03 0.022 (.033) 0.022 (.033) 0.022 (.033) 0.022 (.033)

G3 Intercept 7.0 6.997 (.204) 6.997 (.204) 6.997 (.204) 7.000 (.204)
Linear slope −0.1 −0.115 (.183) −0.115 (.183) −0.116 (.183) −0.115 (.183)
Quad slope 0.04 0.045 (.047) 0.045 (.047) 0.045 (.047) 0.045 (.047)

G4 Intercept 6.0 5.987 (.278) 5.987 (.278) 5.989 (.284) 6.000 (.268)
Linear slope −0.6 −0.624 (.257) −0.624 (.257) −0.620 (.347) −0.674 (.286)
Quad slope 0.02 0.020 (.067) 0.020 (.067) 0.017 (.114) 0.020 (.069)

Condition 2: Continuous covariate added
G1 Intercept 5.0 4.986 (.073) 4.986 (.073) 4.986 (.073) 4.986 (.073)
Linear lope 0.1 0.100 (.024) 0.100 (.024) 0.100 (.024) 0.100 (.025)

G2 Intercept 3.0 2.997 (.131) 2.997 (.131) 2.997 (.131) 2.997 (.131)
Linear lope 0.5 0.496 (.043) 0.496 (.043) 0.496 (.043) 0.496 (.043)

G3 Intercept 7.0 7.000 (.185) 7.000 (.185) 7.000 (.185) 6.999 (.186)
Linear lope −0.1 −0.101 (.060) −0.101 (.060) −0.101 (.060) −0.102 (.061)

G4 Intercept 6.0 5.995 (.259) 5.995 (.259) 6.010 (.265) 5.991 (.300)
Linear lope −0.6 −0.592 (.086) −0.592 (.086) −0.607 (.109) −0.590 (.131)

Condition 3: Increased missing proportion (50%)
G1 Intercept 5.0 5.003 (.085) 5.003 (.085) 5.003 (.085) 5.003 (.085)
Linear lope 0.1 0.097 (.031) 0.097 (.031) 0.097 (.031) 0.097 (.031)

G2 Intercept 3.0 3.000 (.151) 3.000 (.151) 3.000 (.151) 3.000 (.151)
Linear lope 0.5 0.500 (.054) 0.500 (.054) 0.500 (.055) 0.500 (.055)

G3 Intercept 7.0 6.981 (.212) 6.981 (.212) 6.981 (.213) 6.981 (.213)
Linear lope −0.1 −0.104 (.078) −0.104 (.078) −0.104 (.078) −0.104 (.079)

G4 Intercept 6.0 5.979 (.290) 5.979 (.290) 5.989 (.308) 5.963 (.319)
Linear lope −0.6 −0.609 (.104) −0.609 (.104) −0.620 (.141) −0.595 (.077)

Condition 4: Decreased sample size (N = 300)
G1 Intercept 5.0 4.991 (.098) 4.991 (.098) 4.991 (.098) 4.991 (.098)
Linear lope 0.1 0.095 (.032) 0.095 (.032) 0.095 (.032) 0.095 (.032)

G2 Intercept 3.0 3.010 (.167) 3.010 (.167) 3.010 (.169) 3.010 (.169)
Linear lope 0.5 0.503 (.055) 0.503 (.055) 0.503 (.055) 0.503 (.055)

G3 Intercept 7.0 6.980 (.196) 6.980 (.196) 6.980 (.197) 6.980 (.157)
Linear lope −0.1 −0.095 (.063) −0.095 (.063) −0.095 (.063) −0.095 (.018)

G4 Intercept 6.0 5.959 (.331) 5.959 (.331) 5.947 (.341) 5.940 (.372)
Linear lope −0.6 −0.607 (.105) −0.607 (.105) −0.595 (.137) −0.588 (.085)

Note. The multi-group latent growth model was based on five indicator variables. Under the ‘Generated’ columns, estimates were from the data sets generated at the normative values. Under the ‘Missing’ and ‘Same’ columns, all the responses on the 5th time point in Group 4 were completely missing and had the same responses, respectively.