Learning Disabilities Diagnostic Inventory (LDDI)

Donald D. Hammill, Ed.D.
Brian R. Bryant, Ph.D.

The LDDI inventory helps professionals identify learning disabilities in children ages 8 to 17, and reveals the extent to which skill patterns in a particular area (e.g., reading or writing) are consistent with those of individuals known to have a learning disability in that area (e.g., dyslexia or dysgraphia). The LDDI can be completed in 10 minutes by a teacher or speech-language pathologist who is familiar with the student’s skills.

The LDDI inventory is composed of six independent scales, each with 15 easy-to-rate items. Stanines are used to identify the likelihood of intrinsic processing disorders in the six areas—Listening, Speaking, Reading, Writing, Mathematics, Reasoning—as well as to conduct a profile analysis to determine the extent to which a student’s LDDI profile reflects that which is associated with learning disabilities. The inventory was normed on 2,152 students with learning disabilities and reports scores in stanines and percentiles.

Scales & Forms

  • Listening
  • Speaking
  • Reading
  • Writing
  • Mathematics
  • Reasoning