Most researchers agree to six primary methods of collecting relevant information: behavioral observation, behavior rating scales,
interviewing, self - report instruments, projective - expressive techniques, and
sociometric techniques (Merrell, 2001).
Interviewing and
sociometric techniques may constitute an important part of an assessment design but would be considered second choices, argues the same author, adding that projective - expressive techniques or objective, self - report instruments may help in further clarification of the results but should only be used in a complimentary manner (Merrell, 2001).