With a minimum of mathematical manipulation, the mean rate of growth per annum can be determined and applied to a known student population. This method is very easy to use. Disadvantages The accuracy of the results may be less than desired. If the assumption that the subject school district, in fact, will grow at a rate similar to a neighboring school district proves incorrect, the projection figures are incorrect. Such an assumption should be based on a thorough analysis of the two school districts and the unequivocal conclusion that comparable growth will occur.
Frequent analysis is necessary to detect differences in growth patterns.
So long as the assumption remains viable, the results may be valuable. When the slightest change in growth patterns occurs, the accuracy of the projection is suspect. This method of projection should probably be used only as a check or back-up for another type of student enrollment projection method.