I've been using this evaluation sheet. It's nothing perfect, but it's better than nothing. Hope this is helpful.
Speaking Evaluation Sheet
Pronunciation (How well does speaker pronounce English sounds)
_____ 5. Has few traces of foreign accent.
_____ 4. Always intelligible though one is conscious of a definite accent.
_____ 3. Pronunciation problems necessitate concentrated listening and occasionally lead to misunderstanding.
_____ 2. Very hard to understand because of pronunciation problems. Must frequently be asked to repeat.
_____ 1. Pronunciation problems so severe as to make speech virtually unintelligible.
Vocabulary (Does speaker use appropriate vocabulary)
_____ 5. Very good use of vocabulary and idioms.
_____ 4. Sometimes uses inappropriate terms and/or must rephrase ideas because of lexical inadequacies.
_____ 3. Frequently uses the wrong words and appears to have inadequate vocabulary.
_____ 2. Misuse of words and very limited vocabulary makes comprehension quite difficult.
_____ 1. Vocabulary limitations so extreme as to make conversation virtually impossible.
Accuracy (Does speaker control grammar appropriate to level)
_____ 5. Make few noticeable errors of grammar or lexis.
_____ 4. A few minor grammatical and lexical errors but this does not obscure meaning.
_____ 3. Several grammatical and lexical errors which occasionally obscure meaning.
_____ 2. Grammatical and lexical errors make comprehension difficult.
_____ 1. Severe grammatical and lexical errors make speech virtually unintelligible.
Communication (How well does speaker communicate ideas)
_____ 5. Excellent. Completely at ease in his/her use of English on all topics discussed.
_____ 4. Good. Expresses himself/herself quite clearly. Experiences little difficulty in using English to communicate.
_____ 3. Although verbal communication is usually fairly satisfactory, there is occasional re-phrasing and re-patterning of sentences.
_____ 2. Own understanding is severely limited. Large number of errors in grammar and lexis.
_____ 1. Extreme difficulty in communication on any subject. Failure to understand adequately and to make himself/herself understood.
Fluency (Does speaker speak with sufficient ease and clarity)
_____ 5. Speaks fluently and without too great an effort with a fairly wide range of expression.
_____ 4. Fairly smooth delivery mostly though speed occasionally affected by language problems.
_____ 3. Has to make an effort for much of the time. Rather halting delivery. Range of expression limited.
_____ 2. Long pauses, halting delivery, almost gives up making an effort at times.
_____ 1. Speech very halting and fragmentary. Conversation virtually impossible