Tag Archives: more or less

Back to front reasoning?

As those of you in the UK will be aware, there is quite a furore at the moment about the likelihood of local public libraries being closed down in response to the Government’s spending cuts. I was intrigued by a story I heard on the radio last week [the gist is can be found on the BBC] because it  demonstrates something which I find very irritating – confusing correlation with causation!

The story suggests that those who use public libraries are likely to be more literate than the average – stating that public libraries are an important contributor to developing literacy. I have no problem with the concept but does the evidence presented actually support the assertion. Surely, it is equally likely that the causal link is the other way round – those who are more literate are more likely to use libraries?

In this case, I think that the assertion has merit but there is a risk that such sloppy thinking could undermine the argument. Connections of this type are put forward with no justification for the proposed causal link. This can get in the way of understanding the real issues.

It could be that:

  • No causal link exists
  • The reverse of the proposed link is true
  • Both items are dependent on some unidentified issue [e.g. population / demographics]

It’s important to bear this in mind when building your case.

Another BBC resource “More or Less” is very good at debunking these spurious claims and encourages the effective use of data and the derived statistics. It’s off air at the moment but the podcasts are  well worth a listen