GWI Core is run on a quarterly basis, with data published 4-8 weeks after each quarter ends.
Our data collection takes place on a monthly basis. This means that, for each wave, a third of the sample is collected in each of the three months comprising that quarter. For example, if we were interviewing 1,500 respondents in given a market, we would interview 500 of them in month 1, another 500 in month 2 and the final 500 in month 3. Each group of 500 would be representative of that market’s online population.
We first moved to this process in 2019, before which we interviewed respondents across the quarter, meaning we may have interviewed more respondents in one month than another.