Friday, March 09, 2012

Thin Ice

Michael Levi says The Death of Outdoor Hockey Has Been Greatly Exaggerated:

So how do the authors end up generating headlines proclaiming that the end of outdoor hockey is nigh? First, they start by narrowing their scope to “Southwest Canada” (read southern British Columbia and southwest Alberta), where temperatures happen to be relatively warm to start with, and where the historical trend in pond hockey viability appears strongest. Then they blindly extrapolate the last thirty years’ trend into the next few decades. Since the area has pretty mild weather (and hence few good outdoor hockey days) to start with, this lets them identify “a foreseeable end to outdoor staking in this region within the next few decades”. (I’m setting aside for now the convenient use of the past three decades’ trend, rather than the full sixty year sample that the authors have; there’s no justification given for that.) Then comes the final step: in talking to the media, the authors don’t bother to point out that their result was only for a small sliver of the country. “In the next 50 years, the skating season could disappear in most of the regions across Canada,” author Lawrence Mysak tells CTV. Good luck finding that claim anywhere in the actual peer reviewed paper.

Here’s a more accurate headline: Casual extrapolation of trends over an arbitrarily chosen period suggest less pond hockey in Cranbrook and more in Cole Harbor. (The authors report a small but statistically insignificant rise in cold days for Atlantic Canada.) Whether you think that’s a blessing or curse depends on whether you prefer Steve Yzerman or Sidney Crosby, but either way, it’s hardly the bombshell the media reports.