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Program: Authors: Publisher: HLM 5 Hierarchical Linear and Nonlinear Modeling Stephen Raudenbush, Tony Bryk, & Richard Congdon Scientific Software International, Inc. (c) 2000 techsupport@ssicentral.com www.ssicentral.com ------------------------------------------------------------------------------Module: HLM2S.EXE (5.00.2045.1) Date: 8 April 2000, Saturday Time: 14:55:22 ------------------------------------------------------------------------------SPECIFICATIONS FOR THIS HLM2 RUN ------------------------------------------------------------------------------Problem Title: NULL MODEL / ONE-WAY ANALYSIS OF VARIANCE The data source for this run = SIOPET.SSM The command file for this run = C:\HLM5S\siopet\null.hlm Output file name = C:\HLM5S\SIOPET\null.OUT The maximum number of level-2 units = 50 The maximum number of iterations = 1000 Method of estimation: restricted maximum likelihood Weighting Specification ----------------------- Level 1 Level 2 Weighting? no no Weight Variable Name The outcome variable is Normalized? no no HELPING The model specified for the fixed effects was: ---------------------------------------------------Level-1 Coefficients ---------------------INTRCPT1, B0 Level-2 Predictors --------------INTRCPT2, G00 The model specified for the covariance components was: --------------------------------------------------------Sigma squared (constant across level-2 units) Tau dimensions INTRCPT1 Summary of the model specified (in equation format) --------------------------------------------------Level-1 Model Y = B0 + R Level-2 Model B0 = G00 + U0 1 Least Squares Estimates ----------------------sigma_squared = 129.67348 Least-squares estimates of fixed effects ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394346 0.360102 87.182 999 0.000 ---------------------------------------------------------------------------- Least-squares estimates of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394346 1.409786 22.269 999 0.000 ---------------------------------------------------------------------------The least-squares likelihood value = -3851.050779 Deviance = 7702.10156 Number of estimated parameters = 1 STARTING VALUES --------------sigma(0)_squared = Tau(0) INTRCPT1,B0 31.75676 99.81511 Estimation of fixed effects (Based on starting values of covariance components) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394354 1.424099 22.045 49 0.000 ---------------------------------------------------------------------------The value of the likelihood function at iteration 1 = -3.249218E+003 Iterations stopped due to small change in likelihood function ******* ITERATION 2 ******* Sigma_squared = Tau INTRCPT1,B0 2 = level-1 residual. Since there are no level-1 predictors, it simply represents the within group variance in helping. 31.75676 99.81511 Tau (as correlations) INTRCPT1,B0 1.000 ---------------------------------------------------Random level-1 coefficient Reliability estimate ---------------------------------------------------INTRCPT1, B0 0.984 ---------------------------------------------------- 2 00 = level-2 residual. Since there are no level-2 predictors, it simply represents the between group variance in helping. The reliability estimates represent the proportion of the variance in the OLS level-1 estimates that is parameter variance. It is essentially a ratio of “true” parameter variance to “observed” parameter variance. The t-test below assesses the fixed effects in the level-2 equations (i.e.,00 ). In this case, the test of 00 is whether the grand mean helping is significantly different from zero. Final estimation of fixed effects: ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394354 1.424099 22.045 49 0.000 ---------------------------------------------------------------------------- Final estimation of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394354 1.409786 22.269 49 0.000 ---------------------------------------------------------------------------- The Chi-square below indicates whether the level-2 variance component is significantly different from zero (i.e., 00 ). In this case, this tests whether the between group variance in helping is significantly different from zero. Final estimation of variance components: ----------------------------------------------------------------------------Random Effect Standard Variance df Chi-square P-value Deviation Component ----------------------------------------------------------------------------INTRCPT1, U0 9.99075 99.81511 49 3129.25201 0.000 level-1, R 5.63531 31.75676 ----------------------------------------------------------------------------Statistics for current covariance components model -------------------------------------------------Deviance = 6498.43618 Number of estimated parameters = 2 One of the purposes of estimating this null model is to assess the degree of between group variance in helping behavior. A common metric for this is the Intra-Class Correlation (ICC). Given that we have partitioned the variance in helping into its within and between components, an ICC can be computed as follows: ICC = / ( +2 ) ICC = 99.82 / (99.82 + 31.76) ICC = .76 Thus, 76 percent of the variance in helping resides between groups. The Chi-square test above indicates that this between group variance is significant; that is, the intercept term significantly varies across groups. 3 Program: Authors: Publisher: HLM 5 Hierarchical Linear and Nonlinear Modeling Stephen Raudenbush, Tony Bryk, & Richard Congdon Scientific Software International, Inc. (c) 2000 techsupport@ssicentral.com www.ssicentral.com ------------------------------------------------------------------------------Module: HLM2S.EXE (5.00.2045.1) Date: 8 April 2000, Saturday Time: 14:46: 8 ------------------------------------------------------------------------------SPECIFICATIONS FOR THIS HLM2 RUN ------------------------------------------------------------------------------Problem Title: RANDOM COEFFICIENT REGRESSION MODEL The data source for this run = siopet.ssm The command file for this run = C:\HLM5S\siopet\r_reg.hlm Output file name = C:\HLM5S\siopet\r_reg.out The maximum number of level-2 units = 50 The maximum number of iterations = 1000 Method of estimation: restricted maximum likelihood Weighting Specification ----------------------- Level 1 Level 2 Weighting? no no Weight Variable Name The outcome variable is Normalized? no no HELPING The model specified for the fixed effects was: ---------------------------------------------------Level-1 Coefficients ---------------------INTRCPT1, B0 % MOOD slope, B1 Level-2 Predictors --------------INTRCPT2, G00 INTRCPT2, G10 '%' - This level-1 predictor has been centered around its grand mean. The model specified for the covariance components was: --------------------------------------------------------Sigma squared (constant across level-2 units) Tau dimensions INTRCPT1 MOOD slope Summary of the model specified (in equation format) --------------------------------------------------Level-1 Model Y = B0 + B1*(MOOD) + R Level-2 Model B0 = G00 + U0 B1 = G10 + U1 4 Note here that I have centered mood around its grand mean; that is, the mood variable represents the deviation of the individual’s score from the grand mean of the sample. Given this, the variance in the intercept term is equal to the between group variance in helping after controlling for mood (i.e., the adjusted between group variance in helping). We will discuss later in the session the implications of these centering decisions for organizational research. The “least-squares” estimates of fixed effects are the OLS regression results. Remember, mood is grand mean centered (mood – grand mean of mood). Least Squares Estimates ----------------------sigma_squared = 46.34416 Least-squares estimates of fixed effects ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394348 0.215277 145.832 998 0.000 For MOOD slope, B1 INTRCPT2, G10 3.889450 0.091745 42.394 998 0.000 ---------------------------------------------------------------------------Least-squares estimates of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.394348 0.876668 35.811 998 0.000 For MOOD slope, B1 INTRCPT2, G10 3.889450 0.245918 15.816 998 0.000 ---------------------------------------------------------------------------The least-squares likelihood value = -3338.072922 Deviance = 6676.14584 Number of estimated parameters = 1 STARTING VALUES --------------sigma(0)_squared = Tau(0) INTRCPT1,B0 MOOD,B1 5.60718 46.31097 0.56111 0.56111 0.95020 Estimation of fixed effects (Based on starting values of covariance components) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.486284 0.968396 32.514 49 0.000 For MOOD slope, B1 INTRCPT2, G10 3.008250 0.145820 20.630 49 0.000 ---------------------------------------------------------------------------The value of the likelihood function at iteration 1 = -2.445746E+003 The value of the likelihood function at iteration 10 = -2.427653E+003 Iterations stopped due to small change in likelihood function ******* ITERATION 11 ******* Sigma_squared = Tau INTRCPT1,B0 MOOD,B1 2 = the level-1 residual variance. We can use this residual variance to compute an R2 for mood as a level-1 predictor. 5.61081 45.63410 0.63550 0.63550 0.12917 R2 = (2 null - 2random reg. ) / 2 null R2 = (31.76 - 5.61) / 31.76 R2 = .82 (see Snijders & Bosker (1994). Modeled variance in two-level models. Sociological methods & research, 22, 342-363, for an alternative R2.) Tau (as correlations) INTRCPT1,B0 1.000 0.262 MOOD,B1 0.262 1.000 5 is now a variance-covariance matrix of the level2 residuals. Since there are still no level-2 predictors, the diagonal elements in represent the between group variance in the intercepts and slopes respectively. The off-diagonal element represents the covariance between the intercepts and slopes. ---------------------------------------------------Random level-1 coefficient Reliability estimate ---------------------------------------------------INTRCPT1, B0 0.987 MOOD, B1 0.541 ---------------------------------------------------- The reliability estimates once again represent the proportion of the variance in the OLS level-1 estimates that are parameter variance. Note that the intercept is considerably more reliable than the slope. The value of the likelihood function at iteration 11 = -2.427653E+003 The outcome variable is HELPING The t-tests indicate that the pooled intercept and pooled level-1 slope are both significantly different from zero. It is the t-test associated with the pooled level-1 slope that is used to test Hypothesis 1. Final estimation of fixed effects: ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.429052 0.960006 32.738 49 0.000 For MOOD slope, B1 INTRCPT2, G10 3.012354 0.068961 43.682 49 0.000 ---------------------------------------------------------------------------- Final estimation of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 31.429052 0.950326 33.072 49 0.000 For MOOD slope, B1 INTRCPT2, G10 3.012354 0.068257 44.133 49 0.000 ---------------------------------------------------------------------------- The Chi-square tests indicate that there is significant between group variance in the intercept and slope parameters across groups. The intercept term represents the between group variance in helping after controlling for mood. In the next model, we will model this variance with proximity. Final estimation of variance components: ----------------------------------------------------------------------------Random Effect Standard Variance df Chi-square P-value Deviation Component ----------------------------------------------------------------------------INTRCPT1, U0 6.75530 45.63410 49 4605.68268 0.000 MOOD slope, U1 0.35941 0.12917 49 110.16628 0.000 level-1, R 2.36871 5.61081 ----------------------------------------------------------------------------Statistics for current covariance components model -------------------------------------------------Deviance = 4855.30564 Number of estimated parameters = 4 6 Program: Authors: Publisher: HLM 5 Hierarchical Linear and Nonlinear Modeling Stephen Raudenbush, Tony Bryk, & Richard Congdon Scientific Software International, Inc. (c) 2000 techsupport@ssicentral.com www.ssicentral.com ------------------------------------------------------------------------------Module: HLM2S.EXE (5.00.2045.1) Date: 8 April 2000, Saturday Time: 14:49: 2 ------------------------------------------------------------------------------SPECIFICATIONS FOR THIS HLM2 RUN ------------------------------------------------------------------------------Problem Title: INTERCEPTS-AS-OUTCOMES The data source for this run = siopet.ssm The command file for this run = C:\HLM5S\siopet\inter.hlm Output file name = C:\HLM5S\siopet\inter.out The maximum number of level-2 units = 50 The maximum number of iterations = 1000 Method of estimation: restricted maximum likelihood Weighting Specification ----------------------- Level 1 Level 2 Weighting? no no Weight Variable Name The outcome variable is Normalized? no no HELPING The model specified for the fixed effects was: ---------------------------------------------------Level-1 Coefficients ---------------------INTRCPT1, B0 % MOOD slope, B1 Level-2 Predictors --------------INTRCPT2, G00 PROX, G01 INTRCPT2, G10 '%' - This level-1 predictor has been centered around its grand mean. The model specified for the covariance components was: --------------------------------------------------------Sigma squared (constant across level-2 units) Tau dimensions INTRCPT1 MOOD slope Summary of the model specified (in equation format) --------------------------------------------------Level-1 Model Y = B0 + B1*(MOOD) + R Level-2 Model B0 = G00 + G01*(PROX) + U0 B1 = G10 + U1 7 Least Squares Estimates ----------------------sigma_squared = Once again, the least-squares estimates represent the OLS results where mood is grand mean centered and proximity is “assigned” down to the individual level. 41.08266 Least-squares estimates of fixed effects ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.714388 0.622483 39.703 997 0.000 PROX, G01 1.261370 0.111137 11.350 997 0.000 For MOOD slope, B1 INTRCPT2, G10 3.975459 0.086712 45.847 997 0.000 ---------------------------------------------------------------------------Least-squares estimates of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.714388 2.523145 9.795 997 0.000 PROX, G01 1.261370 0.422335 2.987 997 0.003 For MOOD slope, B1 INTRCPT2, G10 3.975459 0.222004 17.907 997 0.000 ---------------------------------------------------------------------------The least-squares likelihood value = -3278.716808 Deviance = 6557.43362 Number of estimated parameters = 1 STARTING VALUES --------------sigma(0)_squared = Tau(0) INTRCPT1,B0 MOOD,B1 5.60718 42.29461 -0.21053 -0.21053 1.11501 Estimation of fixed effects (Based on starting values of covariance components) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 25.028366 2.833095 8.834 48 0.000 PROX, G01 1.221252 0.505558 2.416 48 0.020 For MOOD slope, B1 INTRCPT2, G10 3.009646 0.156721 19.204 49 0.000 ---------------------------------------------------------------------------The value of the likelihood function at iteration 1 = -2.444995E+003 The value of the likelihood function at iteration 10 = -2.424730E+003 Iterations stopped due to small change in likelihood function Since we now include a level-2 predictor of the intercept, the elements in no longer represent the var-covar. of the intercepts and slopes. Specifically, the first diagonal element (i.e., 41.68) is the residual variance in the intercept term. The second diagonal element still represents the between group variance in level-1 slopes. ******* ITERATION 11 ******* Sigma_squared = Tau INTRCPT1,B0 MOOD,B1 5.61079 41.67890 -0.08356 Tau (as correlations) INTRCPT1,B0 1.000 -0.036 MOOD,B1 -0.036 1.000 -0.08356 0.12924 We can use this residual variance in the intercepts to compute an R2 for Proximity as a level-2 predictor. R2 = (00; random reg. - 00; proximity model ) / 00; random reg. R2 = (45.63 – 41.68 ) / 45.63 R2 = .09 8 ---------------------------------------------------Random level-1 coefficient Reliability estimate ---------------------------------------------------INTRCPT1, B0 0.985 MOOD, B1 0.541 ---------------------------------------------------- The reliability for the intercept term is now computed using the residual variance in the intercept. Thus, the reliability has dropped to .985 from .987. The t-tests for the fixed effects now assess the significance of the level-2 regression model for the intercept term (00 and 01 , respectively). The test of 01 is the test of Hypothesis 2. The interpretation of 10 remains unchanged (pooled level-1 slope). Final estimation of fixed effects: ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.922580 2.808705 8.873 48 0.000 PROX, G01 1.235956 0.501261 2.466 48 0.018 For MOOD slope, B1 INTRCPT2, G10 3.013404 0.068981 43.684 49 0.000 ---------------------------------------------------------------------------Final estimation of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.922580 2.920104 8.535 48 0.000 PROX, G01 1.235956 0.476908 2.592 48 0.013 For MOOD slope, B1 INTRCPT2, G10 3.013404 0.068234 44.163 49 0.000 ---------------------------------------------------------------------------- The Chi-square tests indicate that after including Proximity, there is still significant variance in the intercept term across groups. This variance could be modeled by additional group-level variables. The Chi-square tests also indicate that there is significant variance in the slopes (related to Hypothesis 3). Our next model will see if proximity is related to this variance. Final estimation of variance components: ----------------------------------------------------------------------------Random Effect Standard Variance df Chi-square P-value Deviation Component ----------------------------------------------------------------------------INTRCPT1, U0 6.45592 41.67890 48 4127.70255 0.000 MOOD slope, U1 0.35950 0.12924 49 110.18076 0.000 level-1, R 2.36871 5.61079 ----------------------------------------------------------------------------Statistics for current covariance components model -------------------------------------------------Deviance = 4849.46082 Number of estimated parameters = 4 9 Program: Authors: Publisher: HLM 5 Hierarchical Linear and Nonlinear Modeling Stephen Raudenbush, Tony Bryk, & Richard Congdon Scientific Software International, Inc. (c) 2000 techsupport@ssicentral.com www.ssicentral.com ------------------------------------------------------------------------------Module: HLM2S.EXE (5.00.2045.1) Date: 8 April 2000, Saturday Time: 14:50:59 ------------------------------------------------------------------------------SPECIFICATIONS FOR THIS HLM2 RUN ------------------------------------------------------------------------------Problem Title: SLOPES-AS-OUTCOMES The data source for this run = siopet.ssm The command file for this run = C:\HLM5S\siopet\slopes.hlm Output file name = C:\HLM5S\siopet\slopes.out The maximum number of level-2 units = 50 The maximum number of iterations = 1000 Method of estimation: restricted maximum likelihood Weighting Specification ----------------------- Level 1 Level 2 Weighting? no no Weight Variable Name The outcome variable is Normalized? no no HELPING The model specified for the fixed effects was: ---------------------------------------------------Level-1 Coefficients ---------------------INTRCPT1, B0 % MOOD slope, B1 Level-2 Predictors --------------INTRCPT2, G00 PROX, G01 INTRCPT2, G10 PROX, G11 '%' - This level-1 predictor has been centered around its grand mean. The model specified for the covariance components was: --------------------------------------------------------Sigma squared (constant across level-2 units) Tau dimensions INTRCPT1 MOOD slope Summary of the model specified (in equation format) --------------------------------------------------Level-1 Model Y = B0 + B1*(MOOD) + R Level-2 Model B0 = G00 + G01*(PROX) + U0 B1 = G10 + G11*(PROX) + U1 10 Least Squares Estimates ----------------------sigma_squared = 40.98631 The least-squares estimates represent the OLS results where mood is grand mean centered, proximity is “assigned” down to individuals and the proximity*mood (grand mean centered) interaction is entered into the equation. Least-squares estimates of fixed effects ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.784955 0.622949 39.786 996 0.000 PROX, G01 1.241624 0.111531 11.133 996 0.000 For MOOD slope, B1 INTRCPT2, G10 4.453726 0.275517 16.165 996 0.000 PROX, G11 -0.090575 0.049533 -1.829 996 0.067 ---------------------------------------------------------------------------Least-squares estimates of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 24.784955 2.493567 9.940 996 0.000 PROX, G01 1.241624 0.421545 2.945 996 0.004 For MOOD slope, B1 INTRCPT2, G10 4.453726 0.756304 5.889 996 0.000 PROX, G11 -0.090575 0.118460 -0.765 996 0.445 ---------------------------------------------------------------------------The least-squares likelihood value = -3279.132496 Deviance = 6558.26499 Number of estimated parameters = 1 STARTING VALUES --------------sigma(0)_squared = 5.60718 Tau(0) INTRCPT1,B0 42.29566 -0.25107 MOOD,B1 -0.25107 1.27823 Estimation of fixed effects (Based on starting values of covariance components) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 25.167937 2.834108 8.880 48 0.000 PROX, G01 1.195398 0.505750 2.364 48 0.022 For MOOD slope, B1 INTRCPT2, G10 2.096086 0.512071 4.093 48 0.000 PROX, G11 0.172432 0.091396 1.887 48 0.065 ---------------------------------------------------------------------------The value of the likelihood function at iteration 1 = -2.448101E+003 The value of the likelihood function at iteration 30 = -2.414026E+003 Iterations stopped due to small change in likelihood function ******* ITERATION 31 ******* Sigma_squared = Tau INTRCPT1,B0 MOOD,B1 Since we now include a level-2 predictor of the slope, both diagonal elements in represent residual variance. Specifically, the first diagonal element (i.e., 42.95) is the residual variance in the intercept term. The second diagonal element is the residual variance in the slopes (i.e., .02). 5.61465 42.94618 0.00716 Tau (as correlations) INTRCPT1,B0 1.000 0.007 MOOD,B1 0.007 1.000 0.00716 0.02207 We can use this residual variance in the slopes to compute an R2 for Proximity as a level-2 predictor of level-1 slopes. R2 = (11; intercepts-as-outcomes. - 11; proximity model ) / 11; inter-as-outcome R2 = (.129 - .022 ) / .129 R2 = .83 11 ---------------------------------------------------Random level-1 coefficient Reliability estimate ---------------------------------------------------INTRCPT1, B0 0.986 MOOD, B1 0.173 ---------------------------------------------------- The reliability for the slope is now computed using the residual variance in the intercept. Thus, the reliability has dropped to .173 from .541. The t-tests for the fixed effects now assess the significance of the level-2 regression model for the slope term (10 and 11 , respectively). The test of 11 is the test of Hypothesis 3. Final estimation of fixed effects: ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 25.140965 2.847498 8.829 48 0.000 PROX, G01 1.194664 0.508198 2.351 48 0.023 For MOOD slope, B1 INTRCPT2, G10 2.064738 0.158144 13.056 48 0.000 PROX, G11 0.179906 0.028447 6.324 48 0.000 ---------------------------------------------------------------------------- Final estimation of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 25.140965 2.985770 8.420 48 0.000 PROX, G01 1.194664 0.483758 2.470 48 0.017 For MOOD slope, B1 INTRCPT2, G10 2.064738 0.167640 12.317 48 0.000 PROX, G11 0.179906 0.033319 5.400 48 0.000 ---------------------------------------------------------------------------- Final estimation of variance components: The Chi-square tests indicate that after including Proximity, there is no longer significant variance in the slopes across groups. ----------------------------------------------------------------------------Random Effect Standard Variance df Chi-square P-value Deviation Component ----------------------------------------------------------------------------INTRCPT1, U0 6.55333 42.94618 48 4122.21950 0.000 MOOD slope, U1 0.14856 0.02207 48 59.21764 0.129 level-1, R 2.36953 5.61465 ----------------------------------------------------------------------------Statistics for current covariance components model -------------------------------------------------Deviance = 4828.05107 Number of estimated parameters = 4 12 Program: HLM 5 Hierarchical Linear and Nonlinear Modeling Authors: Stephen Raudenbush, Tony Bryk, & Richard Congdon Publisher: Scientific Software International, Inc. (c) 2000 ------------------------------------------------------------------------------Module: HLM2S.EXE (5.00.2045.1) Date: 8 April 2000, Saturday Time: 14:53:33 ------------------------------------------------------------------------------SPECIFICATIONS FOR THIS HLM2 RUN ------------------------------------------------------------------------------Problem Title: SLOPES-AS-OUTCOMES / GROUP MEAN CENTERED WITH AVE-MOOD ENTERED The data source for this run = siopet.ssm The command file for this run = C:\HLM5S\siopet\slopes2.hlm Output file name = C:\HLM5S\siopet\slopes2.out The maximum number of level-2 units = 50 The maximum number of iterations = 1000 Method of estimation: restricted maximum likelihood Weighting Specification ----------------------- Level 1 Level 2 Weighting? no no Weight Variable Name The outcome variable is Normalized? no no HELPING The model specified for the fixed effects was: ---------------------------------------------------Level-1 Level-2 Coefficients Predictors -----------------------------------INTRCPT1, B0 INTRCPT2, G00 AVE_MOOD, G01 PROX, G02 * MOOD slope, B1 INTRCPT2, G10 PROX, G11 '*' - This level-1 predictor has been centered around its group mean. The model specified for the covariance components was: --------------------------------------------------------Sigma squared (constant across level-2 units) Tau dimensions INTRCPT1 MOOD slope Summary of the model specified (in equation format) --------------------------------------------------Level-1 Model Y = B0 + B1*(MOOD) + R Level-2 Model B0 = G00 + G01*(AVE_MOOD) + G02*(PROX) + U0 B1 = G10 + G11*(PROX) + U1 13 In this test of the cross-level moderation, I have centered mood around its group mean. There are some arguments in the literature that group mean centering is a better choice of scaling for the level-1 variables when investigating cross-level interactions (i.e., moderation). More specifically, this allows one to separate out the cross-level interaction from a between group-interaction. Raudenbush (1989a,b) as well as Hofmann and Gavin (1998) have recently discussed this in greater detail. We will demonstrate this notion later in the session. Note that, in addition to group mean centering, this model also includes an additional predictor of the intercept; namely, ave_mood. Ave_mood is the average mood within each group (i.e., the mean mood for each group). We will discuss why this variable is included as a predictor of the intercept later in the session. Least Squares Estimates ----------------------sigma_squared = 35.67115 Here the least-squares estimates represent the OLS results where mood is group-mean centered, ave_mood is entered in as a group level variable and proximity*mood (group-mean centered) is entered as the interaction. Thus, there are 4 predictors: mood (grp mean centered), ave_mood, proximity, and the interaction between mood and proximity (mood*proximity). Least-squares estimates of fixed effects ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 -4.744154 0.934278 -5.078 995 0.000 AVE_MOOD, G01 4.946582 0.114113 43.348 995 0.000 PROX, G02 1.370148 0.103952 13.181 995 0.000 For MOOD slope, B1 INTRCPT2, G10 2.028703 0.361477 5.612 995 0.000 PROX, G11 0.184708 0.065270 2.830 995 0.005 ---------------------------------------------------------------------------- Least-squares estimates of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 -4.744154 3.413768 -1.390 995 0.165 AVE_MOOD, G01 4.946582 0.438139 11.290 995 0.000 PROX, G02 1.370148 0.403980 3.392 995 0.001 For MOOD slope, B1 INTRCPT2, G10 2.028703 0.166272 12.201 995 0.000 PROX, G11 0.184708 0.032923 5.610 995 0.000 ---------------------------------------------------------------------------The least-squares likelihood value = -3210.020772 Deviance = 6420.04154 Number of estimated parameters = 1 STARTING VALUES --------------sigma(0)_squared = 5.60718 Tau(0) INTRCPT1,B0 31.75619 0.02801 MOOD,B1 0.02801 0.02752 Estimation of fixed effects (Based on starting values of covariance components) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 -4.760707 3.959427 -1.202 47 0.236 AVE_MOOD, G01 4.949141 0.483588 10.234 47 0.000 PROX, G02 1.370446 0.440566 3.111 47 0.004 For MOOD slope, B1 INTRCPT2, G10 2.033388 0.161959 12.555 48 0.000 PROX, G11 0.183345 0.029116 6.297 48 0.000 ---------------------------------------------------------------------------The value of the likelihood function at iteration 1 = -2.405170E+003 The value of the likelihood function at iteration 25 = -2.405129E+003 Iterations stopped due to small change in likelihood function ******* ITERATION 26 ******* Sigma_squared = 5.61932 Tau INTRCPT1,B0 31.75516 MOOD,B1 0.05813 0.05813 0.01987 Tau (as correlations) INTRCPT1,B0 1.000 0.073 MOOD,B1 0.073 1.000 14 ---------------------------------------------------Random level-1 coefficient Reliability estimate ---------------------------------------------------INTRCPT1, B0 0.991 MOOD, B1 0.159 ---------------------------------------------------- Now that we have chosen group mean centering, note that the intercept model has changed considerably. This is because under group mean centering, the intercept is simply equal to the between group variance in helping; thus, the level-2 intercept model is simply the between group regression between group level helping and the group variables -- in the preceding model the variance in the intercept was equal to the adjusted between group variance in helping (i.e., after controlling for mood). In this model, the cross-level interaction results (i.e., 10 and 11 ) are virtually identical. This, however, will not always be the case. Final estimation of fixed effects: ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 -4.780527 3.958677 -1.208 47 0.234 AVE_MOOD, G01 4.952222 0.483442 10.244 47 0.000 PROX, G02 1.370791 0.440561 3.111 47 0.004 For MOOD slope, B1 INTRCPT2, G10 2.032463 0.157216 12.928 48 0.000 PROX, G11 0.183645 0.028289 6.492 48 0.000 ---------------------------------------------------------------------------- Final estimation of fixed effects (with robust standard errors) ---------------------------------------------------------------------------Standard Approx. Fixed Effect Coefficient Error T-ratio d.f. P-value ---------------------------------------------------------------------------For INTRCPT1, B0 INTRCPT2, G00 -4.780527 3.426374 -1.395 47 0.170 AVE_MOOD, G01 4.952222 0.439851 11.259 47 0.000 PROX, G02 1.370791 0.404053 3.393 47 0.002 For MOOD slope, B1 INTRCPT2, G10 2.032463 0.168370 12.071 48 0.000 PROX, G11 0.183645 0.033537 5.476 48 0.000 ---------------------------------------------------------------------------- Final estimation of variance components: ----------------------------------------------------------------------------Random Effect Standard Variance df Chi-square P-value Deviation Component ----------------------------------------------------------------------------INTRCPT1, U0 5.63517 31.75516 47 5359.09498 0.000 MOOD slope, U1 0.14095 0.01987 48 59.08077 0.131 level-1, R 2.37051 5.61932 ----------------------------------------------------------------------------Statistics for current covariance components model -------------------------------------------------Deviance = 4810.25736 Number of estimated parameters = 4 15