# [R] Significance Help

Michael Bedward michael.bedward at gmail.com
Wed Dec 15 03:28:05 CET 2010

```Hello Samaire,

I don't know much about eyesight measurements (other than that my own
would probably be 0.1, 0.2) but I'll attempt some suggestions...

For objective (1) you will have to define what you mean by
significantly different. If you had data on left/right values from a
larger population to use as a standard you could then compare each
subject's left - right difference to the population.

For objective (2), it would be better if you had forced them to throw
the ball more than 3 times !

glm( hoops ~ lr.diff, family="binomial" )

where hoops is a two column matrix with number of successful throws in
col 1 and number of misses in col 2; lr.diff is absolute value of left
- right value.

Hope this helps.

Michael

On 15 December 2010 08:21, Samaire Holden <samaire44 at hotmail.co.uk> wrote:
>
> I have a set of results where I have the eyesight power of both left and right eyes for each participant (e.g. 0.75, 0.5). Each participant then had to throw basketballs into a hoop and the number of successful throws was recorded.
>
> I would like to do two things:
> 1. Test whether the eyesight power of the left and right eyes are significantly different from each other.
> 2. Test whether the number of successful throws is significantly affected by eyesight power (i.e. is there a difference between those people who have similar powers in left and right eyesight, to those who have significantly different powers?)
>
> I know that I may not have explained this particularly well, but I'm totally stumped as to where to start! I have only had basic lessons with R and now have to do this report!
>
> Many thanks, Samaire
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>
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