jamovi

Hi, I would like to calculate rater reliability which is available in the Seolmatrix module. I have a set of 6 people and their performances are rated by 50 raters. The ratings can be between 1 and 6 but often the raters use a more restricted range when they give ratings (for example, they score the six performances either 3, 4, 5 or 6 and do not use the lower scores at all).
When I add all the raters for the analysis, I get an error message 'S' is not a positive definite. I would greatly appreciate help in understanding why this is happening.