March 19, 2019

Q&A – Calculating average ROI for a group of students


Great question from Pamela:

Oregon sped regulations for LD referral through RTI specify that ROI needs to be calculated for the RTI group so that the individual ROI can be compared to the RTI group ROI. How do I set up an Excel spreadsheet for that purpose? Do I average CBM scores across students in the group and then compare the group linear regression statistic to the individual linear regression statistic? How do I get Excel to fill in the average for me?


If you used a spreadsheet similar to the ones on this web site, individual student ROI is calculated for you.  If you highlighted that column, you could enter a formula that will calculate the average of those ROIs to give you a group comparison.  To answer your question directly, yes that is one way you could calculate average group ROI.