Quota of participant assessments needed in each category of the VROOM and OMO scales to make statistical comparisons
| VROOM integers | 0 blind | 1–10 | 11–20 | 21–30 | 31–40 | 41–50 | Total |
| Quota | 50 | 50 | 50 | 50 | 50 | 50 | 300 |
| OMO integers | _ | 1–10 | 11–20 | 21–30 | 31–40 | 41–50 | |
| Quota | _ | 50 | 50 | 50 | 50 | 50 | 250 |
O&M, orientation and mobility; OMO, O&M outcomes; VROOM, vision-related outcomes in orientation and mobility.