Implementing a scientifically based educational intervention in mainstream primary schools before and during COVID-19 era: Evidence from Greek-speaking children.

The children were not randomly assigned to groups, and the paper does not report blinding or dropout. The sample was 72 Greek monolingual children from 2 mainstream primary schools, with no reported mental, hearing, visual or serious health problems, so the results may not apply to other languages, school settings, or children with other conditions. The control groups received usual classroom literacy activities, not a matched active program, so the study cannot separate the effect of morphological content from extra classroom activity, teacher attention, or materials. The training was brief and delivered during pandemic disruption, and the paper reports the period as 2 months in one place and 3 months in another. The authors state that wider samples, broader age ranges, and longer follow-up are needed.

Do not read the gains as proof that morphological instruction alone caused improvement. The training was delivered by class teachers with materials, classroom group work, and remote support through Skype, and the groups were not randomly assigned, so the contribution of any single component cannot be separated.