Overview of the 2017 Spoken CALL Shared Task

Research output: Chapter in Book/Report/Conference proceedingConference contribution


  • Claudia Baur
  • Cathy Chua
  • Johanna Gerlach
  • Manny Rayner
  • Helmer Strik

Colleges, School and Institutes

External organisations

  • University of Geneva
  • Radboud Univ Nijmegen


We present an overview of the shared task for spoken CALL. Groups competed on a prompt-response task using English language data collected, through an online CALL game, from Swiss German teens in their second and third years of learning
English. Each item consists of a written German prompt and an audio file containing a spoken response. The task is to accept linguistically correct responses and reject linguistically incorrect ones, with “linguistically correct” being defined by a gold standard derived from human annotations; scoring was
performed using a metric defined as the ratio of the relative rejection rates on incorrect and correct responses. The task received twenty entries from nine different groups. We present the task itself, the results, a tentative analysis of what makes items challenging, a comparison between different metrics, and
suggestions for a continuation.


Original languageEnglish
Title of host publicationProceedings of the 7th ISCA Workshop on Speech and Language Technology in Education
EditorsO Engwall, J Lopes, I Leite
Publication statusPublished - 25 Aug 2017


  • CALL, Shared Task, Automatic speech recognition, Metrics