Sec. 300.304 (b)

(b) Conduct of evaluation. In conducting the evaluation, the public agency must—

(1) Use a variety of assessment tools and strategies to gather relevant functional, developmental, and academic information about the child, including information provided by the parent, that may assist in determining—
(i) Whether the child is a child with a disability under §300.8; and
(ii) The content of the child’s IEP, including information related to enabling the child to be involved in and progress in the general education curriculum (or for a preschool child, to participate in appropriate activities);
(2) Not use any single measure or assessment as the sole criterion for determining whether a child is a child with a disability and for determining an appropriate educational program for the child; and
(3) Use technically sound instruments that may assess the relative contribution of cognitive and behavioral factors, in addition to physical or developmental factors.