# Hypothesis Tests and Edexcel

Recently I have been covering hypothesis tests with both my Year 12 and Year 13 further maths groups and I noticed differing wordings in exam mark schemes (Edexcel S2).

I’ve always taught that you cannot say “we accept $$H_0$$” as you can’t prove that $$H_0$$ is correct, and that you should say something like “There is insufficient evidence to reject $$H_0$$“. However, as the example below from January 2013 shows they seem to be happy with you saying “accept $$H_0$$“:

January 2013

But strangely they don’t always use this language:

May 2011

I’m interested – how do you teach it?

## One thought on “Hypothesis Tests and Edexcel”

1. I would probably argue that “accept H_0” doesn’t imply that it is necessarily true, just that it is the thing you are accepting, and our broader knowledge as stasticians tells us that when someone makes a statistical claim then it is true only as far as a degree of significance. In the same way, saying “reject H_0” doesn’t mean it’s necessarily false. That said, when writing out my own solutions I am more likely to write something like “There is (in)sufficient evidence to accept/reject the manufacturer’s/instructor’s/researcher’s/trapeze artist’s claim” as a concluding statement.

The real shame is that Type I and Type II errors don’t appear until S4 (though of course you can discuss them earlier). I think they help students get a better idea that you are delivering a verdict with doubt built in.