A survey has a response rate, which is the percentage of surveys returned or taken out of the total population invited to respond. Let’s say a trade group sent a survey to 200 general counsel and 80 took the survey. That is a 40 percent response rate.
That survey has an effective response rate, however, because some of the respondents did not provide complete data. Perhaps of the 80 surveys returned, 10 had material data omissions, which then means the effective response rate was 35 percent.
Finally, a few surveys further reduce the respondent numbers because their data, although complete, is on its face wrong. Minus those, you have an accurate effective rate. If a general counsel said the legal department has two lawyers and an internal budget of $20 million, something is wrong with one of those two numbers (or both). In the survey sent to 200, the accurate effective rate drops a half percent for every reply that has facially inaccurate data.