Utterance Segmentation

Determining an utterance

Determining what constitutes an utterance for speakers with language impairments is not always a straightforward task because intelligibility and/or prosody may be impaired. Utterance segmentation is relatively easy when the speaker produces short, simple utterances preceded and followed by utterances of another speaker. For example,
   E What color is this?
   C Yellow.
   E That/'s right.

Utterance segmentation becomes more complicated when the speaker produces complex utterances or multiple utterances per speaking turn. Although you may define your own rules for segmenting utterances, the samples stored in the SALT reference databases were segmented into communication units. The only exceptions are the samples stored in the Bilingual Story Retell databases. These samples were segmented into modified communication units.

Communication units (C-units)

A communication unit is defined as "an independent clause and its modifiers". It is an utterance that cannot be further divided without the disappearance of its essential meaning, or a subordinate clause that is part of the independent predication. In all cases, the words comprising communication units are either independent grammatical predications or propositions, or answers to questions that lack only the repetition of the question elements to satisfy the criterion of independent predication. Consider the following example,

In this example, the two independent clauses stand on their own and are segmented. Contrast this with this next example,

In this example, the second clause, "and bit the boy on his nose", is missing the subject and is therefore dependent on the first clause. It is not segmented.

Refer to Segmenting Utterances into C-units for a detailed description of the rules and lots of examples.

Modified Communication Units

Modified communication units were developed specifically for the bilingual databases to facilitate consistency in the transcription of both Spanish and English narrative samples. To be consistent with the pronoun-drop nature of Spanish, utterances containing successions of verbs without stated subjects were segmented. For example,
   C The gopher look/ed out of the hole.
   C and bit the boy.

   C The frog jump/ed.
   C and land/ed in the water.
   C and got away from the boy.

These examples consist of independent clauses and dependent clauses. With regular communication units, these would be one utterance. But with modified communication units, the dependent clauses are segmented because the subject is implied from the preceding utterance.