The ACTFL oral proficiency interview (OPI) and the Interagency Language Roundtable (ILR) scale provide both a testing method and a set of rating factors for evaluating proficiency. Both are closely related to actual language tasks identified as critical for government employees. Over time, the scale has been expanded to include four skills, a system of levels, and the testing needs of numerous organizations. At the Defense Language Institute Foreign Language Center (DLIFLC), analyses of the proficiency levels into a functional trisection consisting of task, content, and accuracy have fostered use of the OPI and ILR scale in teaching as well as testing. The article begins with a background discussion of the OPI and the ILR scale, then focuses on the trisection and its implications for instruction. (Contains 4 notes.)