Abstract
We propose two novel manipulation strategies
for increasing and decreasing the difficulty of
C-tests automatically. This is a crucial step
towards generating learner-adaptive exercises
for self-directed language learning and preparing language assessment tests. To reach the
desired difficulty level, we manipulate the size
and the distribution of gaps based on absolute and relative gap difficulty predictions. We
evaluate our approach in corpus-based experiments and in a user study with 60 participants.
We find that both strategies are able to generate
C-tests with the desired difficulty level