Hallo everyone, I got a problem while running a PSM on SPSS 20. I have (apparently) correctly installed the R plug-in 2.12.1, SPSS R Essenstial, and installed the file psmatching_2.spd by running SPSS 20 as administrator. The button "PS matching" appeared, but when I runned a PSM (moreover on different datasets) this is the output I received. SET SEED = 1234. SET PRINTBACK=NONE. Warning message: In library(MatchIt, logical.return = TRUE) : there is no package called 'MatchIt' Warning message: In...