To determine the winners, Energage conducted a scientific survey. The Tribune did not pay Energage. The Tribune used advertising to seek nominations. In total, 4,702 companies were invited to participate, compared with 3,323 in 2020. Of those, a record-breaking 295 companies completed the survey (185 last year), allowing Energage to identify the top organizations, divided into three categories: small (fewer than 250 employees), midsize (250-999) and large (1,000 or more), the same divisions as previous surveys. The surveyed companies collectively employ 159,903 people in the Chicago area, of which 140,199 received surveys and 80,917 responded.
