Under the 'DASHBOARD' – 'Speed Index' tab, the table shows units that completed the survey too quick. Too quick means that the time of the respondent, who participated in the survey, on a particular page of the questionnaire ranged from 0 to 10 percent of the fastest units. The Speed Index is calculated in the following manner:
1. We calculate the median for each survey page.
2. We define the respondents separately for each page, namely:
- We assign value 1 to respondents' times that are greater or equal to the median value;
- To the respondents' times, that are lower than the median value, we assign a value obtained by the following formula:
3. We sum up the obtained values (X) for individual respondent by individual pages and divide with the number of pages he visited.
4. The value – time located in an interval between 0 and 10 percent is defined as a too quick respondent.
- Value 1 means that the respondent’s time on the individual page of the survey is above the median value;
- The respondent's time approaching the value 0 indicates the respondent with the response time below the median value.
In case of too quick units, there is a certain risk that the observed units represent a worse quality of data (sufficiency strategy).