They should be useful for press stories in the coming two weeks. Starting yesterday, which was the start of our 4th round of reports, we have slightly altered the format of the presentation. Our current periodization scheme is to use a 7-day segmentation strategy. It should be noted that the third period of study was shorter than the first two, by definition, but the shortened period of fieldwork has been compensated by our switch to interview registered voters only after 27 August, which increased the sub-sample size of registered voters. We will continue to use this format in this round of daily release.
Accumulated data has the merit of larger sample size and therefore smaller sampling error.
Its disadvantage is insensitivity to current changes. Segmented analysis, on the other hand, is much more sensitive to changes, but because such samples are inevitably small, fluctuations due to sampling error become more serious. Analysed on a weekly basis, Liu was ahead of Tsang in the first week, but was behind Tsang in the second week. Analysed across time, it seems that the margin between the candidates are closing up, and Chan's lead is waning. The two candidates are very close together in terms of recognition and support rating, as both are well-known figures.