glmer中的互动(统计建议)

时间:2019-03-25 14:20:21

标签: lme4 interaction

我需要帮助来理解和跟踪使用lme4的glmer()获得的交互。

数据来自语言处理实验,该实验研究了三个分类变量(控制/ copula /性别)对二项式响应(优选或不推荐)的影响。每个实验因素都有两个级别: 控制(对象/对象) copula(ser / estar) 性别(男性/女性)。

我运行以下模型:

...
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...

这些是我获得的结果:

model1= glmer(preferences~control*copula*gender+(1|participant), family=binomial, data=data2)

Generalized linear mixed model fit by maximum likelihood (Laplace Approximation) ['glmerMod'] Family: binomial ( logit ) Formula: preferences_narrow ~ control * copula * gender + (1 | participant) Data: data2 AIC BIC logLik deviance df.resid 1208.6 1261.1 -595.3 1190.6 2517 Scaled residuals: Min 1Q Median 3Q Max -8.6567 0.1970 0.2337 0.2883 0.5371 Random effects: Groups Name Variance Std.Dev. participant (Intercept) 0.254 0.504 Number of obs: 2526, groups: participant, 105 Fixed effects: Estimate Std. Error z value Pr(>|z|) (Intercept) 2.5034 0.2147 11.660 < 2e-16 *** controlsubject 0.4882 0.3172 1.539 0.12380 copulaser 0.4001 0.3237 1.236 0.21646 gendermasc -0.4524 0.2659 -1.701 0.08888 . controlsubject:copulaser -1.0355 0.4526 -2.288 0.02215 * controlsubject:gendermasc 0.5790 0.4430 1.307 0.19121 copulaser:gendermasc 1.7343 0.5819 2.980 0.00288 ** controlsubject:copulaser:gendermasc -1.3121 0.7540 -1.740 0.08181 . --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Correlation of Fixed Effects: (Intr) cntrls coplsr gndrms cntrlsbjct:c cntrlsbjct:g cplsr: contrlsbjct -0.602 copulaser -0.588 0.401 gendermasc -0.724 0.488 0.479 cntrlsbjct:c 0.415 -0.701 -0.716 -0.342 cntrlsbjct:g 0.432 -0.716 -0.287 -0.599 0.502 cplsr:gndrm 0.332 -0.223 -0.556 -0.457 0.397 0.274 cntrlsbjc:: -0.252 0.421 0.430 0.352 -0.600 -0.588 -0.772 controlsubject:copulaser有两个重要的交互。

我跟进了使用em语的第一次互动:

copulaser:gendermasc

结果似乎表明,多种对比推动了互动(当我对第二次互动进行相同操作时,也会发生类似的情况):

emmeans(model1, list(pairwise ~ control + copula), adjust = "tukey")

但是,NOTE是什么意思?

NOTE: Results may be misleading due to involvement in interactions
$`emmeans of control, copula`
 control copula   emmean        SE  df asymp.LCL asymp.UCL
 object  estar  2.277256 0.1497913 Inf  1.983670  2.570841
 subject estar  3.054906 0.1912774 Inf  2.680009  3.429802
 object  ser    3.544448 0.2697754 Inf  3.015698  4.073198
 subject ser    2.630568 0.1752365 Inf  2.287110  2.974025

Results are averaged over the levels of: gender 
Results are given on the logit (not the response) scale. 
Confidence level used: 0.95 

$`pairwise differences of control, copula`
 contrast                       estimate        SE  df z.ratio p.value
 object,estar - subject,estar -0.7776499 0.2215235 Inf  -3.510  0.0025
 object,estar - object,ser    -1.2671927 0.2910689 Inf  -4.354  0.0001
 object,estar - subject,ser   -0.3533119 0.2088155 Inf  -1.692  0.3279
 subject,estar - object,ser   -0.4895427 0.3138092 Inf  -1.560  0.4017
 subject,estar - subject,ser   0.4243380 0.2396903 Inf   1.770  0.2877
 object,ser - subject,ser      0.9138807 0.3048589 Inf   2.998  0.0145

Results are averaged over the levels of: gender 
Results are given on the log odds ratio (not the response) scale. 
P value adjustment: tukey method for comparing a family of 4 estimates 

这是跟进这些互动的好程序吗?

提前谢谢! :)

1 个答案:

答案 0 :(得分:0)

如注释所示,显示的估计值是对照,系膜和性别组合的预测平均值,按性别平均。同时,该模型包括性别与其他两个因素之间的相互作用,这表明这些平均值可能没有意义。您可以通过构建3种预测的图表来形象化这一点:

emmip(model1, gender ~ control * copula)

如果一个案例与另一个案例的预测结果相差很大,那么它们的平均值将是无稽之谈。但是,如果它们的比较几乎相同,则可以平均它们。这就是警告的内容。

我猜测您参加是为了担心与性别的互动-在这种情况下,您应该分别进行比较:

emmeans(model1, pairwise ~ control * copula | gender)