tag:blogger.com,1999:blog-4052593945054595675.post8409074173486238664..comments2024-03-28T14:16:10.498+11:00Comments on Dr Kevin Bonham: Poll Roundup: A Brief History Of Disaster Bounces Kevin Bonhamhttp://www.blogger.com/profile/06845545257440242894noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4052593945054595675.post-72648718670155643202014-07-28T01:04:17.306+10:002014-07-28T01:04:17.306+10:00I'd estimate the MOE of the aggregate at a typ...I'd estimate the MOE of the aggregate at a typical point of the polling cycle - considered just in isolation and ignoring the surrounding readings - to be about 1.3 points. It is higher during quiet periods and lower when there's lots of polling. It's actually a question I can't answer precisely even at a given time, because while pollsters supply a sample size, they don't detail the amount of scaling in their samples, and the more scaling of a sample, the more variable the results are for a given sample size. Also there is the question of whether to take into account the observed "underdispersed" nature of certain polls in calculating the aggregate's MOE - if this is done then it becomes smaller.<br /><br />As a general rule, I'd be confident that a gap of a point or more between any two readings (whatever the time gap between them) is real *unless* one of those points represents a one-week spike, or was taken during a quiet period. On the spiky aggregate graph in this article there are such one-week irregularities in weeks 19 and 35 - these were caused by individual polls that were both bordering on rogue status. While the difference between two independent readings could be approaching 2 points without being "statistically significant", if such a difference occurred it would most likely be because the two readings were at opposite extremes of the non-rogue error spectrum, meaning that they would be highly likely to be corrected in the next reading.Kevin Bonhamhttps://www.blogger.com/profile/06845545257440242894noreply@blogger.comtag:blogger.com,1999:blog-4052593945054595675.post-41179157115292982002014-07-27T12:51:28.980+10:002014-07-27T12:51:28.980+10:00G'day Kevin,
What is the margin of error on yo...G'day Kevin,<br />What is the margin of error on your aggregate and what sort of change over what time period would you consider significant?Sneaky Petehttps://www.blogger.com/profile/07231996579833886940noreply@blogger.com