Methods used include collecting word lists,[7] playing recorded texts to assess comprehension,[8][9] sentence repetition tests,[10] questionnaires,[11] group and individual interviews, retelling of stories,[12] direct observation,[13] pointing to pictures after listening to instructions,[14] and even internet surveys[15][16] There is a growing trend to involve communities more in language survey, using a variety of methods.
Also, the reliability of the results varies according to the method and the rigor with which it is applied, proper sampling technique, etc.
Surveys have also been conducted by ethnic associations (Saskatchewan 1991), government agencies (Statistics Canada 1993), NGO's (Toba, et al. 2002), foundations (Pew Hispanic Center 2004), etc.
The single agency conducting the most language surveys around the world is SIL International (Summer Institute of Linguistics).
[21] Sentence Repetition Tests[22] have also been used for assessing people's ability in a sign language.