Language sample analysis (LSA) is commonly used to monitor progress for children with language disorders (Pavelko et al., 2016). For children with grammar goals, pediatric speech-language pathologists report mean length of utterance (MLU) and type–token ratio (TTR) as the two LSA measures most commonly used (Finestack & Satterlund, 2018). For focused grammatical intervention, these measures may be ineffective in capturing treatment growth. In this clinical focus article, we provide a preliminary comparison of four measures that could be considered as progress monitoring tools following intervention for one finiteness marker.

Pre- and posttreatment spontaneous language samples from six children with developmental language disorder who underwent treatment for the third-person singular –s (–3s) morpheme were analyzed qualitatively. Four measures are reported: MLU, TTR, percent accuracy of –3s, and Tense and Agreement Productivity score of –3s (cf. Hadley & Short, 2005).

Increases were most common across participants in measures that examined use of the treatment target (i.e., percent accuracy and Tense and Agreement Productivity score of –3s). Changes in MLU were not always congruent with measures of the treatment target. Change was mostly not appreciable for TTR.

For preschool-aged children with developmental language disorder, MLU and TTR may not be effective as the sole outcome measures following treatment of –3s. Our six case studies highlight the benefit of measuring the treated skill as discretely as possible and with multiple measures. More research is needed into the use of LSA for outcome measures in children with language disorders.