Explicit tier two vocabulary instruction for young deaf children.

There was no control group; each child served as their own control, so gains cannot be separated from general development or classroom instruction. The sample was very small (n=20) and heterogeneous, limiting generalisability. The subgroup analysis was exploratory and retrospective, not pre-registered. Maintenance was assessed only 8-10 weeks post-intervention, so long-term retention is unknown. The study did not measure whether learned words were used in functional communication or academic tasks, only knowledge of the specific target words.

The study was funded by the Victorian Deaf Education Institute. The authors declared no other conflicts of interest.

Do not assume this program works equally well for all deaf children. The children with the lowest baseline vocabulary learned very few words and retained even fewer, suggesting the standard grade-level targets were not appropriate for them without major modification.