IRIS is designed to improve primary school teachers' use of dialogue and feedback through using video technology for collaborative teacher development with a view to improving academic outcomes for pupils. It is based around a video technology system (IRIS Connect) which enables teachers to record, edit, and comment on teaching and learning. In this pilot, the project comprised six 'film club' events each lasting two hours: three in which teachers reviewed lesson clips from other schools, two in which they reviewed each other's lessons, and one film club in which they reviewed their experience. The project aimed to create long-term, whole-school change, embedding the use of dialogue and feedback in school culture. This evaluation, however, focused specifically on the impact of IRIS Connect on the teachers attending film clubs, as stated in the original protocol agreed prior to the project starting. Schools were free to choose which teachers participated in the trial, but were encouraged to focus on Year 5 pupils. Teachers worked collaboratively in the 'film clubs' to review lesson clips from other schools and to plan, teach, record, and review their own lessons using the IRIS Connect online platform. The project was designed and supported by IRIS Connect and Whole Education with advice from academics at the Universities of Cambridge and Leeds, and additional content from Routledge. This pilot project evaluated: (1) how teachers implemented the intervention; and (2) the change in teachers' thinking and practice. Teachers participating in the project were compared with other teachers in their schools who did not participate. The project lasted for seven months from January to July 2016. The first three clubs in each school were held between January and April and the second three between May and July. Twelve schools were initially recruited for the project, eleven of which participated. Key conclusions from the evaluation are: (1) The overwhelming majority of teachers who responded to the survey believed that the intervention was a good use of their time and had improved their practice; (2) During the seven-month pilot, three of the eleven participating schools chose not to engage with the second half of the project in which teachers videoed their own lessons; (3) The intervention demanded a substantial proportion of teachers' development time. A further trial should provide schools with sufficient time to build this into their annual plans and to embed the intervention in their plans for school improvement; (4) Ten of the eleven participating schools reported that they would continue to use IRIS Connect after the pilot had ended; and (5) The training materials are well developed, clearly understood by teachers, and ready for trial.