The utility of school-age narrative microstructure indices: INMIS and the proportion of restricted utterances.

Purpose: This research investigated the applicability of the index of narrative microstructure (INMIS; L. M. Justice et al., 2006) system for narratives that were elicited through a wordless picture book context. In addition, the viability of an alternative, simpler metric was explored.

Method: Narrative transcripts using the Frog, Where Are You? (M. Mayer, 1969) wordless picture book with 48 school-age children with and without language impairment were analyzed using the INMIS productivity and complexity indices and a proportion of restricted utterances metric. Roy-Bargmann stepdown F calculations, effect sizes, confidence intervals, and positive and negative likelihood ratios were analyzed to examine the statistical and clinical significance of each narrative metric.

Results: The INMIS complexity metric and the proportion of restricted utterances metric yielded statistically significant differences between the two language ability groups and are likely to have good potential as research and clinical tools within the wordless picture book narrative elicitation context. The INMIS productivity metric did not differentiate between the language groups.

Conclusion: The results support the use of the INMIS complexity metric in a wordless picture book elicitation context and introduce an alternative microstructure analysis metric, the proportion of restricted utterances, which uses a logically transparent scale and may meet research and clinical needs without requiring the use of specialized software or complex calculations.