-adiff: Performs contrasts between levels of factor ‘a’ (or -bdiff for factor ‘b’, -cdiff for factor ‘c’, etc), with no collapsing across levels of factor ‘a’.

• • -adiff: Performs contrasts between levels of factor ‘a’ (or -bdiff for factor ‘b’, -cdiff for factor ‘c’, etc), with no collapsing across levels of factor ‘a’.
  • • E.g.1, Factor ‘a’ Category --> 3 levels: (1)Telephone, (2)Email, (3) Face-to-Face
    • • • -adiff 1 2 TvsE
        • -adiff 1 3 TvsF
        • -adiff 2 3 EvsF
  • -acontr: Estimates contrasts among levels of factor ‘a’ (or -bcontr for factor ‘b’, -ccontr for factor ‘c’, etc). Allows for collapsing across levels of factor ‘a’
  • • E.g.1, Factor ‘a’ Category --> 3 levels: (1)Telephone, (2)Email, (3) Face-to-Face
    • -acontr -1 .5 .5EFvsT
    • -acontr .5 .5 -1 TEvsF
    • -acontr .5 -1 .5 TFvsE