April 13, 2023

Briefly

  • How to win at roulette. No, they haven’t repealed the martingale optional stopping theorem, but no mathematical model is a perfect description of reality
  • Farah Hancock has a good series of reports about Auckland and Wellington buses, for Radio NZ.
  • “At the outset, it’s important to note that the finding that “exercise is better than medicine” for depression is one that you cannot possibly make from this paper, because the authors *literally excluded papers that compared exercise to medication*”a Twitter thread on claims about a new study
  • Riding an electric bike drops heart and cancer risks, finds German studyExcept it doesn’t.  The published German study compares exercise levels and accident rates of a group of people riding electric and acoustic bikes. That’s all it does. Unsurprisingly, it finds that the e-bikers still get exercise, but not quite as much as the people using traditional bicycles.  There’s a lot of claims of evidence of major  health effects, that the researchers are supposed to have described to Der Spiegel (I don’t subscribe, so I can’t check).  These are (a) unpublished, and (b) can’t be as described — the study included about 2000 reasonably healthy participants and ran for twelve months, so it can’t possibly have collected substantial evidence about prevention of cancer or Alzheimer’s or heart disease.  That’s before we even get to any issues about confounding: how much does your health affect cycling vs cycling affecting your health.  As a long-term e-cyclist, I’d love these claims to be based on convincing evidence, but they just aren’t.
  • Via David Rumsey on Twitter, the first ‘flow’ visualisation maps, from the 1838 Irish Railway Commission Atlas
  • From Kieran Healy, the relationship between height and number of points scored in the US professional basketball league. No, there isn’t a visually clear relationship. That’s because you’re selecting everyone for being very good at basketball, and the shorter guys need to be better in other ways to compensate.  Height obviously matters; other things matter too.  In the same ways, using some sort of standardised test as a criterion for university admission will make it look as if the test isn’t related to performance at university.
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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Eric Crampton

    Huh. I had no clue that pedal bikes are now called ‘acoustic’ bikes.

    It’s … jarring.

    1 year ago

  • avatar
    Megan Pledger

    I guess I would like height versus points per playing time and a model that adjusted for opposition ability (better players face tougher opposition). And it would be interesting to know shots successfully attempted per playing time versus height – I would assume the smaller players have a higher three point rate.

    1 year ago

  • avatar

    Was going to chime in on ‘acoustic’ bikes but Eric got there first.

    My guess is the translator either confused bikes with guitars or it is a joke that doesn’t quite translate from German.

    But does it open the possibility of an electric bike that goes up to 11?

    1 year ago

    • avatar
      Thomas Lumley

      “Acoustic bike” is Richard Easther’s joke

      1 year ago