There is a new Best Evidence in Brief and this time I picked this study from this biweekly newsletter written up by Justin Hill:

Emily K. Snell and colleagues recently conducted a randomized controlled trial to assess the effectiveness of a texting-based vocabulary program for prekindergarten students within an urban school district. The study consisted of 346 students (173 assigned to the treatment group and 173 assigned to the control group) in 49 classrooms (24 assigned to the treatment group and 25 assigned to the control group) and took place over 7 months, with 5 of those months devoted to the intervention and 1 month at both the beginning and end devoted to testing. Teachers in the treatment group received training and were instructed to send text messages to parents each week with four vocabulary words being targeted for the week, as well as links to child-friendly definitions, images, and ideas for activities.

A comparison of post-test and pre-test scores revealed that children in the treatment group demonstrated significantly greater vocabulary learning than those in the control group (d = 0.17, p < .05). However, this effect is relatively small and is approximately equal to learning 1 more word than the control group on a 20-word vocabulary assessment. Analysis of scores on the Peabody Picture Vocabulary Test-4 did not reveal significant differences between the two groups, suggesting the intervention did not influence general vocabulary acquisition. However, the texts may have boosted family engagement with vocabulary, as 82% of parents reported reviewing the word definitions at least a few times per week. It may have also helped to improve parent-teacher communication, as 78% of teachers reported feeling more connected to families. Overall, these results suggest a small but potentially meaningful impact could result from the implementation of a text-based vocabulary program.