Ottawa's program of middle French immersion (MFI) instruction, beginning in fourth grade, was evaluated when the first cohort reached sixth grade. Results of the study were compared with those of other groups, particularly the early French immersion (EFI) program and late French immersion (LFI) program students. The evaluation also added data from the third fourth-grade MFI cohort to expand the grade four database. Information was gathered through questionnaires, tracing of student progress, and collection of standardized test scores. The sixth-grade MFI cohort consisted of two classes (about 40 students). They were matched with sixth-grade EFI classes with similar reading scores. The MFI grade four cohort consisted of five classes. Results suggest that, despite comparable French production skills, the EFI and MFI cohorts should be merged in grade seven with caution and with follow-up research. The third MFI grade four cohort was found to be similar to the first. The MFI program appeared to attract, in general, more able students and the children of more educated and participatory parents. Few MFI students had been EFI students previously. The first MFI cohort has been reduced by one-third. Substantial appended materials include tests and student progress data. (MSE)