Daily or weekly? The role of treatment frequency in the effectiveness of grammar treatment for children with specific language impairment

Abstract

This study compared the effectiveness of a school-based treatment for expressive grammar in 5-year-olds with specific language impairment delivered in two different dose frequencies: eight sessions delivered daily over 8 consecutive school days or eight sessions delivered weekly over 8 consecutive weeks. Eighteen children received treatment daily and 13 children received treatment weekly. In both groups, treatment consisted of eight 1-hour sessions of small group activities in a classroom setting. Techniques included explicit instruction, focused stimulation, recasting, and imitation. Results were analysed at the group level and as a case series with each child as their own control in a single-subject design. The 8-weeks group showed significantly greater gain in test scores over the treatment period than in an equal time period prior to treatment, whereas the 8-days group did not (Cohen's d = 1.64 for 8-weeks group). Single-subject analyses indicated that 46% of children in the 8-week group and 17% of children in the 8-day group showed a significant treatment effect. It is concluded that expressive grammar treatment was most effective when dose frequency was weekly over 8 weeks rather than daily over 8 days for 5-year-old children with specific language impairment.

Keywords::

• Treatment effectiveness
• specific language impairment
• treatment frequency
• grammar intervention
• morpho-syntax

Acknowledgements

This work was funded by the Australian Research Council Centre of Excellence for Cognition and its Disorders (CE110001021) http://www.ccd.edu.au. We would like to thank research assistants Sarah Arnott, Joanne Dixon, Caroline Dixon, Shannon Golding, Rachel Reid, Lilian Sklarz, and Catherine Wilkinson. We are very grateful to the staff and students at Fremantle and West Coast Language Development Centres for welcoming us so wholeheartedly into their classrooms.

Notes

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes

1. Analyses conducted with pre-treatment gain calculated as the difference between Test 3 and an average of Test 1 and Test 2 yielded identical results, as did an analysis using each child's highest pre-treatment test score.

2. As seen in Table I, four children in the 8-weeks group were tested using the CELF-P rather than the CELF-P2. As no children in the 8-days group received this test, we have no t-test comparison for these children.

3. Non-parametric tests yielded identical results, as did a comparison of the mean of test 1 and test 2 scores and of test 2 scores.

4. While written records of the sessions were kept by the teachers, observation of the treatment sessions suggested that the records were not sufficiently accurate for research purposes. The teachers were focused on the activity, the treatment techniques, and behaviour management, as well as completing the online record. While the teachers insist it was a very valuable tool for them to monitor dose and the children's responses, we were not sufficiently confident of their accuracy to use them to calculate dose.