Null statistical significance

We had another stupid survey (bordering on the insanely idiotic) this morning from the BBC. They wanted to ‘highlight’ the depraved depths of behaviours within Parliament and have repeatedly announced that a quarter of those working in parliament had either suffered or witnessed sexual harassment within the Houses within the last year. This headline is drawn from a survey carried out by across party group within Westminster.

It said its survey, which got 1,377 responses, or 17% of the Westminster workforce, found that as well as 19% reporting experience of sexual harassment, 39% had experienced non-sexual harassment or bullying in the past 12 months.

This ignores or begs several questions. First, why is there such a very small reply? 17% out of such a small, closed and, by definition, opinionated and active group of people. It refers to responses, which might suggest that all or nearly all were asked. It does rather shout out that the survey does not have the respect or acceptance of that group.
That group is of course also self selected. Those who have cause to be interested may be expected to reply. Those with no interest, or cause to be interested,
Second, ‘19% reporting experience of’ sexual harassment. What is ‘experience of’? Apparently – according to the BBC – this includes witnessing somebody else suffering sexual harassment. As presented, this figure is exactly consistent with a single incident, perhaps of a female MP wolf whistling at a workman in the hall of Parliament. 300 might hear it, and therefore ‘experience sexual harassment’. No doubt the reality is rather worse, but the figure as presented gives no actual reason for concluding that it was.

Leave a comment