Surveys that are more qualitative in nature have been conducted in the field. I am going to say a few brief words about mixed or exogamous unions. People have said that they are a disaster, because as soon as francophones marry anglophones, they start to use English. However, research shows that francophones who are more inclined to use English within an exogamous couple, have, in many cases, already shown a significant interest in English, be it from a very young age, or at least since the age of 15. So previous behaviour is important.
We also know that access to education in one's own language definitely influences future behaviour. In Manitoba, for example, a very high proportion of francophones did not have access to French schools. Some of them attended English high schools, and others studied in both languages. These people have a very strong bilingual identity. That factor undoubtedly influences perceptions in terms of identity and linguistic practices.