Discourse Completion Task: Its Validity and Reliability in Research Projects on Speech Acts

The article examines the issue of the reliability and validity of the discourse completion task (DCT) in research projects on speech acts. It starts with a review of the main data collection methods in pragmatics. In the paper, the advantages and disadvantages of using a questionnaire for gathering data are discussed. Next, the studies comparing questionnaire data with natural spoken data are presented. The paper argues that relying on one data collection instrument, namely a DCT, does not yield reliable results; therefore the integration of authentic and controlled data is desirable. It is concluded that the study of a particular speech act cannot be carried out without some reliance on naturally occurring data.