It is planned that a major study will begin shortly in Institiúid Teangeolaíochta Éireann to determine the amount of Irish acquired by leaving certificate students on leaving school.
I am not aware of any current research which attempts to compare or evaluate different methods of teaching Irish on a large scale, but this type of research is no longer common. It is more usual nowadays for teachers to come together in smaller localised groups to conduct their own study of current practice and to experiment with new teaching methods and materials.
For a number of years now, work has been going on in collaboration between the curriculum development unit of the City of Dublin Vocational Education Committee and Institiúid Teangeolaíochta Éireann on teaching methods and materials for the foundation level courses at junior and leaving certificate. New materials are produced and piloted in 15 Dublin schools.
The Department is currently supporting a research project entitled "Gaeilge ag obair/Irish works sa scoil". This involves a selection of second level schools. The aims of the project include the production of guidelines which school communities will find useful in helping to create an Irish-bilingual atmosphere. The project will focus, inter alia, on the school plan, the transition year, extra-curricular activities and school communication, internal and external.