SPLIT FILE OFF.
EXAMINE VARIABLES=M1_CIV_MEAN M2_CIV_MEAN
  /PLOT BOXPLOT HISTOGRAM NPPLOT
  /COMPARE GROUPS
  /STATISTICS DESCRIPTIVES EXTREME
  /CINTERVAL 95
  /MISSING LISTWISE
  /NOTOTAL.
syntax -->
SORT CASES  BY HS.
SPLIT FILE SEPARATE BY HS.
EXAMINE VARIABLES=M1_CIV_MEAN M2_CIV_MEAN
  /PLOT BOXPLOT HISTOGRAM NPPLOT
  /COMPARE GROUPS
  /STATISTICS DESCRIPTIVES EXTREME
  /CINTERVAL 95
  /MISSING LISTWISE
  /NOTOTAL.