Table 3: Weight matrices for weighted kappas.

A - Weight matrix for items with all four categories used by the raters
No difficulties Slight difficulties Moderate difficulties Severe difficulties
No difficulties 1 0.42 0.18 0
Slight difficulties - 1 0.42 0.18
Moderate difficulties - - 1 0.42
Severe difficulties - - - 1
B - Weight matrix for items with three categories used by the raters
- No difficulties Slight difficulties Moderate difficulties
No difficulties 1 0.29 0
Slight difficulties - 1 0.29
Moderate difficulties - - 1