Animal experiments

Ever thought your cat might be trolling you? Turns out you’re right. As explained in this New Scientist article, recent Japanese research concludes that cats are entirely capable of recognising their names; they just choose not to when it suits them.

The full details of the experiment are included in a research report published in Nature. It’s an interesting, though not entirely easy, read. But I’d like to use it to point out an aspect of statistical methodology that is often ignored: statistical analyses don’t usually start with the analysis of data; they start with the design of the experiment by which the data are to be collected. And it’s essential that an experiment is designed correctly in order to be able to use Statistics to answer the question you’re interested in.

So, in this particular study, the researchers carried out four separate experiments:

  • In experiment 1, the ability of cats to distinguish their own names from that of other similar nouns was tested;
  • In experiment 2, cats living with numerous other cats were tested to see if they could distinguish their own name from that of other cats in the same household;
  • Experiment 3 was like experiment 1, but using cats from a ‘cat cafe‘ (don’t ask) rather than a normal household;
  • Experiment 4 was also like experiment 1, but using a voice other than the cat’s owner to trigger the responses.

Through this sequence of experiments, the researchers were able to judge whether or not the cats genuinely recognise and respond to their own names in a variety of environments, and to exclude the possibility that the responses were due to factors other than actual name recognition. As such, this is a great example of how the design of an experiment has been carefully tailored to ensure that a statistical analysis of the data it generates is able to answer the question of interest.

I won’t go into details, but there are many other aspects of the experimental design that also required careful specification:

  1. The number of cats to be included in the study;
  2. The choice of words to use as alternative stimuli to the cats’ names, and the order in which they are used;
  3. The definitions of actions that are considered positive responses to stimuli;
  4. The protocol for determining whether a cat has responded positively to a stimuli or not;

amongst others. Full details are available in the Nature article, as indeed are the data, should you wish to analyse them yourself.

In the context of sports modelling, these kinds of issues are less explicit, since analyses are usually retrospective, using data that have already been historically collected and stored. Nonetheless, the selection of which data to include in an analysis can affect the analysis, and it’s important to ensure that results are not sensitive to specific, subjective choices. However, for analyses of data that include a decision process – such as betting strategies – it may well be relevant to formulate an experimental design for a prospective study, comparing results based on one type of strategy, compared with that of another. We’ll discuss strategies for this type of experiment in a future post.

 

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