An estimate of an individual student’s rate of improvement needs least three data points — because one needs at least three points to calculate “slope” of “change over time”, which is the basic formula for “rate of improvement”. The three data points can be a fall benchmark and then two progress monitoring measures or three progress monitoring measures — all of the same measure type. Ideally, the measures should be administered far enough apart so that the student might be expected to show some improvement (a minimum of 2 weeks for the basic literacy measures such as LN, LS, SEG, WRF, PRF and a minimum of 3 weeks for the more challenging constructs such as math, vocabulary, and reading comprehension).
Take the hoped for score and subtract the student’s fall benchmark score from that number. This will give you the number of points a student needs to improve on that measure in order to meet the grade-level expectations by the winter or spring. Then, estimate the number of days in between the day the student took the first test and the date or point in time selected.
Divide the total number of points needed to reach grade-level proficiency by the number of days in between first and estimated last test, and that will give you the required rate of improvement for the student to reach the grade-level proficiency goal by the time selected.