John Robertson found This is School:

• Moderately reduces teacher workload“The marking and monitoring of student progress is made very much easier, the same is true of creating worksheets to go with video content.”
• Moderately improves teaching efficiency“This depends on what teaching efficiency is taken to mean, but I think exposing students to multiple native speakers is a great thing to be able to do in a classroom.”
• Does not significantly improve teacher wellbeing“I think teachers will certainly enjoy using the site, but that their wellbeing is typically dependent on other aspects of the job.”
• Moderately improves attainment“Listening and reading skills are most improved along with vocabulary learning.”
• Moderately builds student knowledge“As above really - vocabulary knowledge is increased as well as knowledge about different accents of native speakers”