Conduct these analyses (1) uncentered, (2) group-mean centered, and
(3) grand-mean centered.
(1) Uncentered
# Fit the model
model2 <- lmer(n_math ~
n_reading +
n_ses +
n_men +
n_white +
(1 | sid), data = data5)
# Display the results
summary(model2)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading + n_ses + n_men + n_white + (1 | sid)
## Data: data5
##
## REML criterion at convergence: 102762.6
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.7533 -0.6734 -0.0655 0.6229 4.5674
##
## Random effects:
## Groups Name Variance Std.Dev.
## sid (Intercept) 3.766 1.941
## Residual 42.817 6.544
## Number of obs: 15459, groups: sid, 880
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 1.775e+01 3.352e-01 1.434e+04 52.939 < 2e-16 ***
## n_reading 6.312e-01 6.067e-03 1.539e+04 104.040 < 2e-16 ***
## n_ses 2.018e+00 8.411e-02 1.441e+04 23.989 < 2e-16 ***
## n_men 1.633e+00 1.083e-01 1.522e+04 15.086 < 2e-16 ***
## n_white 5.218e-01 1.373e-01 1.055e+04 3.801 0.000145 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_rdng n_ses n_men
## n_reading -0.910
## n_ses 0.392 -0.324
## n_men -0.269 0.123 -0.065
## n_white -0.185 -0.108 -0.179 -0.017
report(model2)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading, n_ses, n_men and n_white (formula: n_math ~
## n_reading + n_ses + n_men + n_white). The model included sid as random effect
## (formula: ~1 | sid). The model's total explanatory power is substantial
## (conditional R2 = 0.56) and the part related to the fixed effects alone
## (marginal R2) is of 0.52. The model's intercept, corresponding to n_reading =
## 0, n_ses = 0, n_men = 0 and n_white = 0, is at 17.75 (95% CI [17.09, 18.40],
## t(15452) = 52.94, p < .001). Within this model:
##
## - The effect of n reading is statistically significant and positive (beta =
## 0.63, 95% CI [0.62, 0.64], t(15452) = 104.04, p < .001; Std. beta = 0.63, 95%
## CI [0.62, 0.64])
## - The effect of n ses is statistically significant and positive (beta = 2.02,
## 95% CI [1.85, 2.18], t(15452) = 23.99, p < .001; Std. beta = 0.15, 95% CI
## [0.14, 0.17])
## - The effect of n men is statistically significant and positive (beta = 1.63,
## 95% CI [1.42, 1.85], t(15452) = 15.09, p < .001; Std. beta = 0.08, 95% CI
## [0.07, 0.09])
## - The effect of n white is statistically significant and positive (beta = 0.52,
## 95% CI [0.25, 0.79], t(15452) = 3.80, p < .001; Std. beta = 0.02, 95% CI [0.01,
## 0.04])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
visualize(model2, plot = "model")
## Note: You didn't choose to plot n_white so I am inputting the median

(2) Group-mean centered (within group)
# Making group mean (school mean) variables
group_means <- data5 %>%
group_by(sid) %>%
summarise(
n_reading_group_mean = mean(n_reading, na.rm = TRUE),
n_ses_group_mean = mean(n_ses, na.rm = TRUE),
n_men_group_mean = mean(n_men, na.rm = TRUE),
n_white_group_mean = mean(n_white, na.rm = TRUE)
)
# Merge the group means back into the original data
data6 <- inner_join(data5, group_means, by = "sid")
# Perform group-mean centering
data6 <- data6 %>%
mutate(
n_reading_centered = n_reading - n_reading_group_mean,
n_ses_centered = n_ses - n_ses_group_mean,
n_men_centered = n_men - n_men_group_mean,
n_white_centered = n_white - n_white_group_mean
)
# Fit the model
model3 <- lmer(n_math ~
n_reading_centered +
n_ses_centered +
n_men_centered +
n_white_centered +
(1 | sid), data = data6)
# Display the results
summary(model3)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_centered + n_ses_centered + n_men_centered +
## n_white_centered + (1 | sid)
## Data: data6
##
## REML criterion at convergence: 103907.2
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.6195 -0.6641 -0.0671 0.6168 4.4732
##
## Random effects:
## Groups Name Variance Std.Dev.
## sid (Intercept) 21.6 4.648
## Residual 42.8 6.542
## Number of obs: 15459, groups: sid, 880
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 5.010e+01 1.672e-01 8.537e+02 299.604 <2e-16 ***
## n_reading_centered 6.232e-01 6.205e-03 1.457e+04 100.429 <2e-16 ***
## n_ses_centered 1.771e+00 8.955e-02 1.458e+04 19.779 <2e-16 ***
## n_men_centered 1.642e+00 1.099e-01 1.458e+04 14.939 <2e-16 ***
## n_white_centered 2.261e-01 1.554e-01 1.457e+04 1.455 0.146
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_rdn_ n_ss_c n_mn_c
## n_rdng_cntr 0.000
## n_ses_cntrd -0.003 -0.289
## n_men_cntrd 0.002 0.122 -0.061
## n_wht_cntrd 0.000 -0.079 -0.151 -0.013
report(model3)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_centered, n_ses_centered, n_men_centered and
## n_white_centered (formula: n_math ~ n_reading_centered + n_ses_centered +
## n_men_centered + n_white_centered). The model included sid as random effect
## (formula: ~1 | sid). The model's total explanatory power is substantial
## (conditional R2 = 0.57) and the part related to the fixed effects alone
## (marginal R2) is of 0.36. The model's intercept, corresponding to
## n_reading_centered = 0, n_ses_centered = 0, n_men_centered = 0 and
## n_white_centered = 0, is at 50.10 (95% CI [49.77, 50.43], t(15452) = 299.60, p
## < .001). Within this model:
##
## - The effect of n reading centered is statistically significant and positive
## (beta = 0.62, 95% CI [0.61, 0.64], t(15452) = 100.43, p < .001; Std. beta =
## 0.56, 95% CI [0.55, 0.57])
## - The effect of n ses centered is statistically significant and positive (beta
## = 1.77, 95% CI [1.60, 1.95], t(15452) = 19.78, p < .001; Std. beta = 0.11, 95%
## CI [0.10, 0.12])
## - The effect of n men centered is statistically significant and positive (beta
## = 1.64, 95% CI [1.43, 1.86], t(15452) = 14.94, p < .001; Std. beta = 0.08, 95%
## CI [0.07, 0.09])
## - The effect of n white centered is statistically non-significant and positive
## (beta = 0.23, 95% CI [-0.08, 0.53], t(15452) = 1.46, p = 0.146; Std. beta =
## 7.82e-03, 95% CI [-2.72e-03, 0.02])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
(3) Grand-mean centered
# Perform grand-mean centering
data6 <- data6 %>%
mutate(
n_reading_grand_mean_centered = n_reading - mean(n_reading, na.rm = TRUE),
n_ses_grand_mean_centered = n_ses - mean(n_ses, na.rm = TRUE),
n_men_grand_mean_centered = n_men - mean(n_men, na.rm = TRUE),
n_white_grand_mean_centered = n_white - mean(n_white, na.rm = TRUE)
)
# Fit the model
model4 <- lmer(n_math ~
n_reading_grand_mean_centered +
n_ses_grand_mean_centered +
n_men_grand_mean_centered +
n_white_grand_mean_centered +
(1 | sid), data = data6)
# Display the results
summary(model4)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_grand_mean_centered + n_ses_grand_mean_centered +
## n_men_grand_mean_centered + n_white_grand_mean_centered + (1 | sid)
## Data: data6
##
## REML criterion at convergence: 102762.6
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.7533 -0.6734 -0.0655 0.6229 4.5674
##
## Random effects:
## Groups Name Variance Std.Dev.
## sid (Intercept) 3.766 1.941
## Residual 42.817 6.544
## Number of obs: 15459, groups: sid, 880
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 5.031e+01 8.564e-02 8.236e+02 587.476 < 2e-16
## n_reading_grand_mean_centered 6.312e-01 6.067e-03 1.539e+04 104.040 < 2e-16
## n_ses_grand_mean_centered 2.018e+00 8.411e-02 1.441e+04 23.989 < 2e-16
## n_men_grand_mean_centered 1.633e+00 1.083e-01 1.522e+04 15.086 < 2e-16
## n_white_grand_mean_centered 5.218e-01 1.373e-01 1.055e+04 3.801 0.000145
##
## (Intercept) ***
## n_reading_grand_mean_centered ***
## n_ses_grand_mean_centered ***
## n_men_grand_mean_centered ***
## n_white_grand_mean_centered ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_r___ n_s___ n_m___
## n_rdng_gr__ 0.003
## n_ss_grnd__ -0.004 -0.324
## n_mn_grnd__ 0.003 0.123 -0.065
## n_wht_grn__ 0.010 -0.108 -0.179 -0.017
report(model4)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_grand_mean_centered,
## n_ses_grand_mean_centered, n_men_grand_mean_centered and
## n_white_grand_mean_centered (formula: n_math ~ n_reading_grand_mean_centered +
## n_ses_grand_mean_centered + n_men_grand_mean_centered +
## n_white_grand_mean_centered). The model included sid as random effect (formula:
## ~1 | sid). The model's total explanatory power is substantial (conditional R2 =
## 0.56) and the part related to the fixed effects alone (marginal R2) is of 0.52.
## The model's intercept, corresponding to n_reading_grand_mean_centered = 0,
## n_ses_grand_mean_centered = 0, n_men_grand_mean_centered = 0 and
## n_white_grand_mean_centered = 0, is at 50.31 (95% CI [50.14, 50.48], t(15452) =
## 587.48, p < .001). Within this model:
##
## - The effect of n reading grand mean centered is statistically significant and
## positive (beta = 0.63, 95% CI [0.62, 0.64], t(15452) = 104.04, p < .001; Std.
## beta = 0.63, 95% CI [0.62, 0.64])
## - The effect of n ses grand mean centered is statistically significant and
## positive (beta = 2.02, 95% CI [1.85, 2.18], t(15452) = 23.99, p < .001; Std.
## beta = 0.15, 95% CI [0.14, 0.17])
## - The effect of n men grand mean centered is statistically significant and
## positive (beta = 1.63, 95% CI [1.42, 1.85], t(15452) = 15.09, p < .001; Std.
## beta = 0.08, 95% CI [0.07, 0.09])
## - The effect of n white grand mean centered is statistically significant and
## positive (beta = 0.52, 95% CI [0.25, 0.79], t(15452) = 3.80, p < .001; Std.
## beta = 0.02, 95% CI [0.01, 0.04])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
Only using the school-level variables to predict the intercept,
conduct these analyses (a) with coefficients for all the student-level
variables fixed and (b) allowing the all student-level coefficients to
randomly vary.
(a-1) Random Intercept Model: Group-Mean Centering with School-Level
Variables
model5 <- lmer(n_math ~
n_reading_centered +
n_ses_centered +
n_men_centered +
n_white_centered +
ns_blkpct +
ns_public +
(1 | sid), data = data6)
summary(model5)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_centered + n_ses_centered + n_men_centered +
## n_white_centered + ns_blkpct + ns_public + (1 | sid)
## Data: data6
##
## REML criterion at convergence: 102098.1
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.6256 -0.6649 -0.0659 0.6102 4.5121
##
## Random effects:
## Groups Name Variance Std.Dev.
## sid (Intercept) 18.32 4.280
## Residual 42.62 6.529
## Number of obs: 15217, groups: sid, 865
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 5.351e+01 5.133e-01 9.190e+02 104.239 < 2e-16 ***
## n_reading_centered 6.225e-01 6.234e-03 1.436e+04 99.863 < 2e-16 ***
## n_ses_centered 1.772e+00 9.020e-02 1.436e+04 19.642 < 2e-16 ***
## n_men_centered 1.634e+00 1.105e-01 1.436e+04 14.791 < 2e-16 ***
## n_white_centered 1.981e-01 1.563e-01 1.436e+04 1.267 0.20504
## ns_blkpct -6.889e-01 5.978e-02 8.832e+02 -11.524 < 2e-16 ***
## ns_public -1.517e+00 5.283e-01 9.182e+02 -2.871 0.00418 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_rdn_ n_ss_c n_mn_c n_wht_ ns_blk
## n_rdng_cntr 0.000
## n_ses_cntrd 0.000 -0.286
## n_men_cntrd 0.000 0.121 -0.060
## n_wht_cntrd 0.000 -0.080 -0.149 -0.013
## ns_blkpct -0.238 0.000 -0.001 0.003 0.000
## ns_public -0.891 0.000 -0.001 0.000 0.001 -0.108
report(model5)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_centered, n_ses_centered, n_men_centered,
## n_white_centered, ns_blkpct and ns_public (formula: n_math ~ n_reading_centered
## + n_ses_centered + n_men_centered + n_white_centered + ns_blkpct + ns_public).
## The model included sid as random effect (formula: ~1 | sid). The model's total
## explanatory power is substantial (conditional R2 = 0.58) and the part related
## to the fixed effects alone (marginal R2) is of 0.39. The model's intercept,
## corresponding to n_reading_centered = 0, n_ses_centered = 0, n_men_centered =
## 0, n_white_centered = 0, ns_blkpct = 0 and ns_public = 0, is at 53.51 (95% CI
## [52.50, 54.52], t(15208) = 104.24, p < .001). Within this model:
##
## - The effect of n reading centered is statistically significant and positive
## (beta = 0.62, 95% CI [0.61, 0.63], t(15208) = 99.86, p < .001; Std. beta =
## 0.56, 95% CI [0.55, 0.57])
## - The effect of n ses centered is statistically significant and positive (beta
## = 1.77, 95% CI [1.59, 1.95], t(15208) = 19.64, p < .001; Std. beta = 0.11, 95%
## CI [0.10, 0.12])
## - The effect of n men centered is statistically significant and positive (beta
## = 1.63, 95% CI [1.42, 1.85], t(15208) = 14.79, p < .001; Std. beta = 0.08, 95%
## CI [0.07, 0.09])
## - The effect of n white centered is statistically non-significant and positive
## (beta = 0.20, 95% CI [-0.11, 0.50], t(15208) = 1.27, p = 0.205; Std. beta =
## 6.86e-03, 95% CI [-3.75e-03, 0.02])
## - The effect of ns blkpct is statistically significant and negative (beta =
## -0.69, 95% CI [-0.81, -0.57], t(15208) = -11.52, p < .001; Std. beta = -0.17,
## 95% CI [-0.20, -0.14])
## - The effect of ns public is statistically significant and negative (beta =
## -1.52, 95% CI [-2.55, -0.48], t(15208) = -2.87, p = 0.004; Std. beta = -0.04,
## 95% CI [-0.07, -0.01])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
(a-2) Random Intercept Model: Grand-Mean Centering with School-Level
Variables
model6 <- lmer(n_math ~
n_reading_grand_mean_centered +
n_ses_grand_mean_centered +
n_men_grand_mean_centered +
n_white_grand_mean_centered +
ns_blkpct +
ns_public +
(1 | sid), data = data6)
summary(model6)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_grand_mean_centered + n_ses_grand_mean_centered +
## n_men_grand_mean_centered + n_white_grand_mean_centered +
## ns_blkpct + ns_public + (1 | sid)
## Data: data6
##
## REML criterion at convergence: 101045.9
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.7639 -0.6733 -0.0628 0.6213 4.5908
##
## Random effects:
## Groups Name Variance Std.Dev.
## sid (Intercept) 3.396 1.843
## Residual 42.642 6.530
## Number of obs: 15217, groups: sid, 865
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 4.994e+01 2.857e-01 9.562e+02 174.817 < 2e-16
## n_reading_grand_mean_centered 6.302e-01 6.100e-03 1.515e+04 103.309 < 2e-16
## n_ses_grand_mean_centered 2.048e+00 8.448e-02 1.403e+04 24.241 < 2e-16
## n_men_grand_mean_centered 1.617e+00 1.088e-01 1.500e+04 14.859 < 2e-16
## n_white_grand_mean_centered 2.677e-01 1.418e-01 1.185e+04 1.888 0.059
## ns_blkpct -2.534e-01 3.372e-02 9.824e+02 -7.513 1.30e-13
## ns_public 1.194e+00 2.928e-01 9.483e+02 4.076 4.96e-05
##
## (Intercept) ***
## n_reading_grand_mean_centered ***
## n_ses_grand_mean_centered ***
## n_men_grand_mean_centered ***
## n_white_grand_mean_centered .
## ns_blkpct ***
## ns_public ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_r___ n_s___ n_m___ n_w___ ns_blk
## n_rdng_gr__ -0.056
## n_ss_grnd__ -0.057 -0.319
## n_mn_grnd__ 0.009 0.122 -0.065
## n_wht_grn__ -0.062 -0.097 -0.171 -0.013
## ns_blkpct -0.237 0.039 0.007 0.010 0.248
## ns_public -0.898 0.047 0.057 -0.012 -0.020 -0.101
report(model6)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_grand_mean_centered,
## n_ses_grand_mean_centered, n_men_grand_mean_centered,
## n_white_grand_mean_centered, ns_blkpct and ns_public (formula: n_math ~
## n_reading_grand_mean_centered + n_ses_grand_mean_centered +
## n_men_grand_mean_centered + n_white_grand_mean_centered + ns_blkpct +
## ns_public). The model included sid as random effect (formula: ~1 | sid). The
## model's total explanatory power is substantial (conditional R2 = 0.56) and the
## part related to the fixed effects alone (marginal R2) is of 0.52. The model's
## intercept, corresponding to n_reading_grand_mean_centered = 0,
## n_ses_grand_mean_centered = 0, n_men_grand_mean_centered = 0,
## n_white_grand_mean_centered = 0, ns_blkpct = 0 and ns_public = 0, is at 49.94
## (95% CI [49.38, 50.50], t(15208) = 174.82, p < .001). Within this model:
##
## - The effect of n reading grand mean centered is statistically significant and
## positive (beta = 0.63, 95% CI [0.62, 0.64], t(15208) = 103.31, p < .001; Std.
## beta = 0.63, 95% CI [0.61, 0.64])
## - The effect of n ses grand mean centered is statistically significant and
## positive (beta = 2.05, 95% CI [1.88, 2.21], t(15208) = 24.24, p < .001; Std.
## beta = 0.16, 95% CI [0.14, 0.17])
## - The effect of n men grand mean centered is statistically significant and
## positive (beta = 1.62, 95% CI [1.40, 1.83], t(15208) = 14.86, p < .001; Std.
## beta = 0.08, 95% CI [0.07, 0.09])
## - The effect of n white grand mean centered is statistically non-significant
## and positive (beta = 0.27, 95% CI [-0.01, 0.55], t(15208) = 1.89, p = 0.059;
## Std. beta = 0.01, 95% CI [-4.72e-04, 0.03])
## - The effect of ns blkpct is statistically significant and negative (beta =
## -0.25, 95% CI [-0.32, -0.19], t(15208) = -7.51, p < .001; Std. beta = -0.06,
## 95% CI [-0.08, -0.05])
## - The effect of ns public is statistically significant and positive (beta =
## 1.19, 95% CI [0.62, 1.77], t(15208) = 4.08, p < .001; Std. beta = 0.03, 95% CI
## [0.02, 0.05])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
(b-1) Random Slope Model: Group-Mean Centering with School-Level
Variables
# Specify the model with fixed student-level coefficients
model7 <- lmer(
n_math ~
n_reading_centered +
n_ses_centered +
n_men_centered +
n_white_centered +
ns_blkpct +
ns_public +
(1+ n_reading_centered | sid),
data = data6
)
## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, :
## Model failed to converge with max|grad| = 0.0482497 (tol = 0.002, component 1)
## Warning in checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv, : Model is nearly unidentifiable: very large eigenvalue
## - Rescale variables?
# Print the model summary
summary(model7)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_centered + n_ses_centered + n_men_centered +
## n_white_centered + ns_blkpct + ns_public + (1 + n_reading_centered |
## sid)
## Data: data6
##
## REML criterion at convergence: 102035.5
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.3873 -0.6617 -0.0765 0.6108 4.5118
##
## Random effects:
## Groups Name Variance Std.Dev. Corr
## sid (Intercept) 18.400775 4.2896
## n_reading_centered 0.006037 0.0777 0.63
## Residual 42.117979 6.4898
## Number of obs: 15217, groups: sid, 865
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 5.366e+01 5.024e-01 9.272e+02 106.804 < 2e-16 ***
## n_reading_centered 6.156e-01 6.830e-03 8.409e+02 90.130 < 2e-16 ***
## n_ses_centered 1.752e+00 8.998e-02 1.435e+04 19.473 < 2e-16 ***
## n_men_centered 1.637e+00 1.103e-01 1.436e+04 14.851 < 2e-16 ***
## n_white_centered 2.084e-01 1.562e-01 1.433e+04 1.334 0.182070
## ns_blkpct -6.603e-01 5.833e-02 8.860e+02 -11.321 < 2e-16 ***
## ns_public -1.780e+00 5.159e-01 9.203e+02 -3.449 0.000587 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_rdn_ n_ss_c n_mn_c n_wht_ ns_blk
## n_rdng_cntr 0.068
## n_ses_cntrd -0.006 -0.260
## n_men_cntrd 0.001 0.109 -0.060
## n_wht_cntrd -0.009 -0.075 -0.148 -0.013
## ns_blkpct -0.237 -0.032 0.000 0.004 0.017
## ns_public -0.889 0.016 0.006 -0.002 0.004 -0.108
## optimizer (nloptwrap) convergence code: 0 (OK)
## Model failed to converge with max|grad| = 0.0482497 (tol = 0.002, component 1)
## Model is nearly unidentifiable: very large eigenvalue
## - Rescale variables?
report(model7)
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_centered, n_ses_centered, n_men_centered,
## n_white_centered, ns_blkpct and ns_public (formula: n_math ~ n_reading_centered
## + n_ses_centered + n_men_centered + n_white_centered + ns_blkpct + ns_public).
## The model included n_reading_centered as random effects (formula: ~1 +
## n_reading_centered | sid). The model's total explanatory power is substantial
## (conditional R2 = 0.58) and the part related to the fixed effects alone
## (marginal R2) is of 0.39. The model's intercept, corresponding to
## n_reading_centered = 0, n_ses_centered = 0, n_men_centered = 0,
## n_white_centered = 0, ns_blkpct = 0 and ns_public = 0, is at 53.66 (95% CI
## [52.67, 54.64], t(15206) = 106.80, p < .001). Within this model:
##
## - The effect of n reading centered is statistically significant and positive
## (beta = 0.62, 95% CI [0.60, 0.63], t(15206) = 90.13, p < .001; Std. beta =
## 0.55, 95% CI [0.54, 0.57])
## - The effect of n ses centered is statistically significant and positive (beta
## = 1.75, 95% CI [1.58, 1.93], t(15206) = 19.47, p < .001; Std. beta = 0.11, 95%
## CI [0.10, 0.12])
## - The effect of n men centered is statistically significant and positive (beta
## = 1.64, 95% CI [1.42, 1.85], t(15206) = 14.85, p < .001; Std. beta = 0.08, 95%
## CI [0.07, 0.09])
## - The effect of n white centered is statistically non-significant and positive
## (beta = 0.21, 95% CI [-0.10, 0.51], t(15206) = 1.33, p = 0.182; Std. beta =
## 7.21e-03, 95% CI [-3.38e-03, 0.02])
## - The effect of ns blkpct is statistically significant and negative (beta =
## -0.66, 95% CI [-0.77, -0.55], t(15206) = -11.32, p < .001; Std. beta = -0.17,
## 95% CI [-0.20, -0.14])
## - The effect of ns public is statistically significant and negative (beta =
## -1.78, 95% CI [-2.79, -0.77], t(15206) = -3.45, p < .001; Std. beta = -0.05,
## 95% CI [-0.08, -0.02])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
(b-2) Random Slope Model: Grand-Mean Centering with School-Level
Variables
# Specify the model with random student-level coefficients
model8 <- lmer(
n_math ~
n_reading_grand_mean_centered +
n_ses_grand_mean_centered +
n_men_grand_mean_centered +
n_white_grand_mean_centered +
ns_blkpct +
ns_public +
(n_reading + n_ses + n_men + n_white | sid),
data = data6,
)
## boundary (singular) fit: see help('isSingular')
## Warning: Model failed to converge with 1 negative eigenvalue: -6.1e+01
# Print the model summary
summary(model8)
## Linear mixed model fit by REML. t-tests use Satterthwaite's method [
## lmerModLmerTest]
## Formula: n_math ~ n_reading_grand_mean_centered + n_ses_grand_mean_centered +
## n_men_grand_mean_centered + n_white_grand_mean_centered +
## ns_blkpct + ns_public + (n_reading + n_ses + n_men + n_white | sid)
## Data: data6
##
## REML criterion at convergence: 100937.8
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -3.3664 -0.6675 -0.0746 0.6132 4.5700
##
## Random effects:
## Groups Name Variance Std.Dev. Corr
## sid (Intercept) 12.146531 3.48519
## n_reading 0.006297 0.07936 -0.84
## n_ses 0.718998 0.84794 0.75 -0.27
## n_men 1.437430 1.19893 -0.49 0.33 -0.47
## n_white 2.052109 1.43252 -0.37 0.02 -0.65 0.33
## Residual 41.338020 6.42946
## Number of obs: 15217, groups: sid, 865
##
## Fixed effects:
## Estimate Std. Error df t value Pr(>|t|)
## (Intercept) 4.999e+01 2.958e-01 1.030e+03 168.972 < 2e-16
## n_reading_grand_mean_centered 6.245e-01 6.736e-03 8.204e+02 92.702 < 2e-16
## n_ses_grand_mean_centered 1.973e+00 8.954e-02 8.178e+02 22.033 < 2e-16
## n_men_grand_mean_centered 1.606e+00 1.163e-01 7.923e+02 13.811 < 2e-16
## n_white_grand_mean_centered 3.220e-01 1.489e-01 7.648e+02 2.162 0.030909
## ns_blkpct -2.384e-01 3.192e-02 9.752e+02 -7.468 1.81e-13
## ns_public 1.008e+00 3.029e-01 1.033e+03 3.327 0.000908
##
## (Intercept) ***
## n_reading_grand_mean_centered ***
## n_ses_grand_mean_centered ***
## n_men_grand_mean_centered ***
## n_white_grand_mean_centered *
## ns_blkpct ***
## ns_public ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Correlation of Fixed Effects:
## (Intr) n_r___ n_s___ n_m___ n_w___ ns_blk
## n_rdng_gr__ 0.011
## n_ss_grnd__ -0.041 -0.305
## n_mn_grnd__ 0.033 0.154 -0.120
## n_wht_grn__ -0.069 -0.079 -0.239 0.031
## ns_blkpct -0.223 0.018 0.002 0.008 0.272
## ns_public -0.909 0.055 0.068 -0.010 -0.014 -0.089
## optimizer (nloptwrap) convergence code: 0 (OK)
## boundary (singular) fit: see help('isSingular')
report(model8)
## boundary (singular) fit: see help('isSingular')
## Random effect variances not available. Returned R2 does not account for random effects.
## boundary (singular) fit: see help('isSingular')
## Random effect variances not available. Returned R2 does not account for random effects.
## We fitted a linear mixed model (estimated using REML and nloptwrap optimizer)
## to predict n_math with n_reading_grand_mean_centered,
## n_ses_grand_mean_centered, n_men_grand_mean_centered,
## n_white_grand_mean_centered, ns_blkpct and ns_public (formula: n_math ~
## n_reading_grand_mean_centered + n_ses_grand_mean_centered +
## n_men_grand_mean_centered + n_white_grand_mean_centered + ns_blkpct +
## ns_public). The model included n_reading as random effects (formula: ~n_reading
## + n_ses + n_men + n_white | sid). The model's explanatory power related to the
## fixed effects alone (marginal R2) is 0.55. The model's intercept, corresponding
## to n_reading_grand_mean_centered = 0, n_ses_grand_mean_centered = 0,
## n_men_grand_mean_centered = 0, n_white_grand_mean_centered = 0, ns_blkpct = 0
## and ns_public = 0, is at 49.99 (95% CI [49.41, 50.57], t(15194) = 168.97, p <
## .001). Within this model:
##
## - The effect of n reading grand mean centered is statistically significant and
## positive (beta = 0.62, 95% CI [0.61, 0.64], t(15194) = 92.70, p < .001; Std.
## beta = 0.62, 95% CI [0.61, 0.63])
## - The effect of n ses grand mean centered is statistically significant and
## positive (beta = 1.97, 95% CI [1.80, 2.15], t(15194) = 22.03, p < .001; Std.
## beta = 0.15, 95% CI [0.14, 0.16])
## - The effect of n men grand mean centered is statistically significant and
## positive (beta = 1.61, 95% CI [1.38, 1.83], t(15194) = 13.81, p < .001; Std.
## beta = 0.08, 95% CI [0.07, 0.09])
## - The effect of n white grand mean centered is statistically significant and
## positive (beta = 0.32, 95% CI [0.03, 0.61], t(15194) = 2.16, p = 0.031; Std.
## beta = 0.02, 95% CI [1.79e-03, 0.03])
## - The effect of ns blkpct is statistically significant and negative (beta =
## -0.24, 95% CI [-0.30, -0.18], t(15194) = -7.47, p < .001; Std. beta = -0.06,
## 95% CI [-0.08, -0.04])
## - The effect of ns public is statistically significant and positive (beta =
## 1.01, 95% CI [0.41, 1.60], t(15194) = 3.33, p < .001; Std. beta = 0.03, 95% CI
## [0.01, 0.05])
##
## Standardized parameters were obtained by fitting the model on a standardized
## version of the dataset. 95% Confidence Intervals (CIs) and p-values were
## computed using a Wald t-distribution approximation.
tab_model(model1, model2, model3, model4)
|
|
Math Score
|
Math Score
|
Math Score
|
Math Score
|
|
Predictors
|
Estimates
|
CI
|
p
|
Estimates
|
CI
|
p
|
Estimates
|
CI
|
p
|
Estimates
|
CI
|
p
|
|
(Intercept)
|
50.12
|
49.80 – 50.45
|
<0.001
|
17.75
|
17.09 – 18.40
|
<0.001
|
50.10
|
49.77 – 50.43
|
<0.001
|
50.31
|
50.14 – 50.48
|
<0.001
|
|
Reading Score
|
|
|
|
0.63
|
0.62 – 0.64
|
<0.001
|
|
|
|
|
|
|
|
Socioeconomic Status
|
|
|
|
2.02
|
1.85 – 2.18
|
<0.001
|
|
|
|
|
|
|
|
Gender=Men
|
|
|
|
1.63
|
1.42 – 1.85
|
<0.001
|
|
|
|
|
|
|
|
Race=white
|
|
|
|
0.52
|
0.25 – 0.79
|
<0.001
|
|
|
|
|
|
|
|
Reading Score
|
|
|
|
|
|
|
0.62
|
0.61 – 0.64
|
<0.001
|
|
|
|
|
Socioeconomic Status
|
|
|
|
|
|
|
1.77
|
1.60 – 1.95
|
<0.001
|
|
|
|
|
Gender=Men
|
|
|
|
|
|
|
1.64
|
1.43 – 1.86
|
<0.001
|
|
|
|
|
Race=white
|
|
|
|
|
|
|
0.23
|
-0.08 – 0.53
|
0.146
|
|
|
|
|
Reading Score
|
|
|
|
|
|
|
|
|
|
0.63
|
0.62 – 0.64
|
<0.001
|
|
Socioeconomic Status
|
|
|
|
|
|
|
|
|
|
2.02
|
1.85 – 2.18
|
<0.001
|
|
Gender=Men
|
|
|
|
|
|
|
|
|
|
1.63
|
1.42 – 1.85
|
<0.001
|
|
Race=white
|
|
|
|
|
|
|
|
|
|
0.52
|
0.25 – 0.79
|
<0.001
|
|
Random Effects
|
|
σ2
|
81.01
|
42.82
|
42.80
|
42.82
|
|
τ00
|
19.14 sid
|
3.77 sid
|
21.60 sid
|
3.77 sid
|
|
ICC
|
0.19
|
0.08
|
0.34
|
0.08
|
|
N
|
884 sid
|
880 sid
|
880 sid
|
880 sid
|
|
Observations
|
15648
|
15459
|
15459
|
15459
|
|
Marginal R2 / Conditional R2
|
0.000 / 0.191
|
0.517 / 0.556
|
0.360 / 0.575
|
0.517 / 0.556
|
tab_model(model5, model6)
|
|
Math Score
|
Math Score
|
|
Predictors
|
Estimates
|
CI
|
p
|
Estimates
|
CI
|
p
|
|
(Intercept)
|
53.51
|
52.50 – 54.52
|
<0.001
|
49.94
|
49.38 – 50.50
|
<0.001
|
|
Reading Score
|
0.62
|
0.61 – 0.63
|
<0.001
|
|
|
|
|
Socioeconomic Status
|
1.77
|
1.59 – 1.95
|
<0.001
|
|
|
|
|
Gender=Men
|
1.63
|
1.42 – 1.85
|
<0.001
|
|
|
|
|
Race=white
|
0.20
|
-0.11 – 0.50
|
0.205
|
|
|
|
SCH:Percentage of Black Students
|
-0.69
|
-0.81 – -0.57
|
<0.001
|
-0.25
|
-0.32 – -0.19
|
<0.001
|
|
SCH:School Type=Public
|
-1.52
|
-2.55 – -0.48
|
0.004
|
1.19
|
0.62 – 1.77
|
<0.001
|
|
Reading Score
|
|
|
|
0.63
|
0.62 – 0.64
|
<0.001
|
|
Socioeconomic Status
|
|
|
|
2.05
|
1.88 – 2.21
|
<0.001
|
|
Gender=Men
|
|
|
|
1.62
|
1.40 – 1.83
|
<0.001
|
|
Race=white
|
|
|
|
0.27
|
-0.01 – 0.55
|
0.059
|
|
Random Effects
|
|
σ2
|
42.62
|
42.64
|
|
τ00
|
18.32 sid
|
3.40 sid
|
|
ICC
|
0.30
|
0.07
|
|
N
|
865 sid
|
865 sid
|
|
Observations
|
15217
|
15217
|
|
Marginal R2 / Conditional R2
|
0.393 / 0.576
|
0.524 / 0.559
|
tab_model(model7, model8)
|
|
Math Score
|
Math Score
|
|
Predictors
|
Estimates
|
CI
|
p
|
Estimates
|
CI
|
p
|
|
(Intercept)
|
53.66
|
52.67 – 54.64
|
<0.001
|
49.99
|
49.41 – 50.57
|
<0.001
|
|
Reading Score
|
0.62
|
0.60 – 0.63
|
<0.001
|
|
|
|
|
Socioeconomic Status
|
1.75
|
1.58 – 1.93
|
<0.001
|
|
|
|
|
Gender=Men
|
1.64
|
1.42 – 1.85
|
<0.001
|
|
|
|
|
Race=white
|
0.21
|
-0.10 – 0.51
|
0.182
|
|
|
|
SCH:Percentage of Black Students
|
-0.66
|
-0.77 – -0.55
|
<0.001
|
-0.24
|
-0.30 – -0.18
|
<0.001
|
|
SCH:School Type=Public
|
-1.78
|
-2.79 – -0.77
|
0.001
|
1.01
|
0.41 – 1.60
|
0.001
|
|
Reading Score
|
|
|
|
0.62
|
0.61 – 0.64
|
<0.001
|
|
Socioeconomic Status
|
|
|
|
1.97
|
1.80 – 2.15
|
<0.001
|
|
Gender=Men
|
|
|
|
1.61
|
1.38 – 1.83
|
<0.001
|
|
Race=white
|
|
|
|
0.32
|
0.03 – 0.61
|
0.031
|
|
Random Effects
|
|
σ2
|
42.12
|
41.34
|
|
τ00
|
18.40 sid
|
12.15 sid
|
|
τ11
|
0.01 sid.n_reading_centered
|
0.01 sid.n_reading
|
|
|
|
0.72 sid.n_ses
|
|
|
|
1.44 sid.n_men
|
|
|
|
2.05 sid.n_white
|
|
ρ01
|
0.63 sid
|
-0.84
|
|
|
|
0.75
|
|
|
|
-0.49
|
|
|
|
-0.37
|
|
ICC
|
0.31
|
|
|
N
|
865 sid
|
865 sid
|
|
Observations
|
15217
|
15217
|
|
Marginal R2 / Conditional R2
|
0.387 / 0.577
|
0.545 / NA
|
save.image("Exercise_231019.RData")