Abstract
This study reports on the use of an open-source software for sign language learning and (self-)assessment. A Yes/No vocabulary size test for Swiss German Sign Language (Deutschschweizerische Gebärdensprache, DSGS) was developed, targeting beginning adult learners. The Web-based test, which can be used for self-assessment or placement purposes, was administered to 20 DSGS adult learners of ages 24 to 55 (M = 39.3). The learners filled out a background questionnaire, took the Yes/No test tests, and filled out a feedback questionnaire. The comments provided by the learners about the suitability of the Web-based DSGS vocabulary self-assessment instrument provided concrete feedback towards improvement of the system.