TY - RPRT TI - A probability-based formula for calculating interobserver agreement. AU - A R Yelton AU - B G Wildman AU - M T Erickson PY - 1977 DO - 10.1901/jaba.1977.10-127 UR - https://pubmed.ncbi.nlm.nih.gov/16795541/ ID - 16795541 ER -