# Estimating a student's Rate of Improvement (ROI) and considerations for setting a goal

We can’t get an estimate of an individual student’s rate of improvement until we have at 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 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).

Once the student has taken three different tests of the same test type and grade level, the system will automatically calculate that individual student’s rate of improvement (increase in score per day), which you can access by downloading a .CSV of the report you’re looking at (look for a link to the right).

If, however, you simply want a more general reference of what score might be “expected” on a particular measure at a particular time point in the year, please refer to the Detailed Percentile Lookup Table, where you can find the raw score associated with the different percentile ranks. If your goal is to get the student to “grade level proficiency”, then you would select the raw score that is closest to the 50th percentile (the 50th percentile represents the mathematical “average” for students from that grade level, on that measure, at the time of year you’ve selected (fall, winter, spring). You can then use that “hoped for score” to calculate the ROI for your student.

Take… 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 (depending on which time point you selected).

Then, estimate the number of days in between the day the student took the first test and the winter or spring benchmark date (again, depending on which time point you 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 you’ve selected.