A group of seven Japanese-language Oral Proficiency Interview (OPI) testers licensed by the American Council on the Teaching of foreign Languages (ACTFL) conducted research related to ACTFL-OPI criteria. They first examined 24 audiotaped interview tests to see what kind of consistency there would be when individual testers applied general criteria to actual speech. The raters found very high agreement among themselves. Next, the researchers selected six tapes for detailed analysis that represented typical novice-, intermediate-, and advanced-level speech and analyzed them in an attempt to find a way to make general OPI criteria more specific. Because a majority of current learners who want to have their speaking assessed are intermediate-level speakers, it was decided to focus on that particular level. This paper describes the main differences among the learners' speech on common topics and then presents the distinguishing characteristics of intermediate-level speakers in comparison with those of novice- and advanced-level speakers in categories such as sentence productivity, types of clauses created, rate of success in structuring paragraphs (and quasiparagraphs), handling role plays, uses and misuse of tense, aspects, particles and other grammatical items, and variety of verbs used. (Author/JL)