It is during these years since 1990 that most of the teacher assistants have been added to the system. However, there is room for significantly different mixes of how many teachers and how many TAs. This is shown by a significant variation of teacher-TA ratios in different districts, even though the same provincial formula is applied in supplying funding to those districts. In other words, the service of non-enrolling specialist teachers supporting classroom teachers could have been maintained at 1990 levels while some 3,000 TA positions could still have been created to provide the type of support that is appropriate from TAs, for the same total expenditure. The point of this comparison is not to call for a particular formula for TA and specialist teacher supports.
Several factors are possible explanations for the current trend.
Decisions about providing support are frequently made on an individual student basis rather than on the basis of defining the needs of the school as a whole. When the needs of an individual child are the sole focus, then the cost factor may lead to the immediate conclusion that the only realistic request is for a TA, not a teacher. When these individual decisions are added up, they produce a service model that provides a larger number of people to provide the service. The least-trained adult working in the school may end up providing the service to the students with the greatest needs. The degree of attention the TA provides to one student sometimes has the effect of segregating the student within the class rather than leading to the inclusion that is supposed to be the purpose of the integration policy.