Fig. 2
From: Statistical analysis of two arm randomized pre-post designs with one post-treatment measurement
Diagnosis plots of ANCOVA main and interaction models in heterogeneous scenario. a Scatter plot of baseline and follow-up weights in balanced design. Black and red solid dots are data points in the treatment and control arms. Black and red solid lines are the regression slopes of baseline weight against follow-up weight in the treatment and control arms. b Boxplot of residuals from the treatment and control arms from ANCOVAI model in balanced design; c Boxplot of residuals from the treatment and control arms from ANCOVAII model in balanced design; d Scatter plot of baseline and follow-up weights in unbalanced design. Black and red solid dots are data points in the treatment and control arms. Black and red solid lines are the regression slopes of baseline weight against follow-up weight in the treatment and control arms. e Boxplot of residuals from the treatment and control arms from ANCOVAI model in an unbalanced design; f Boxplot of residuals from the treatment and control arms from ANCOVAII model in an unbalanced design