ICT knowledge and skills are often surveyed by self-assessment questions with a rating scale. However, different respondents might use scale categories differently.
This paper focuses on self-assessments of ICT and humanities students at upper secondary school and their comparison before and after adjustment for differential scale usage. The anchoring vignette method has been used for the adjustement for the heterogeneity in reporting behavior.
We show a high variability of self-assessments and anchoring vignettes evaluations and also big differences between a typical ICT and humanities students before and after adjustment for the scale usage.