>On 8 Dec 1999, Luv 2 muah 143 wrote:
>
>> 5 of 10 volunteers are randomly selected to receive self-defense training.
>> The other 5 receive no training. At the end of the training period, all
>> subjects complete a self-confidence questionnaire.
>>
>> a.) Is there a difference in self-confidence between the 2 groups (p<.01)?
>>
>> b.) What are the effects of self-defense traing on self-confidence (I'm
>> assuming a two-tailed test?). Explain analysis
>>
>> Please help, I can't figure it out...my mind has gone blank!!!!
In article <[EMAIL PROTECTED]>,
Mike Wogan <[EMAIL PROTECTED]> wrote:
>Without a pre-test measure of self-confidence, taken prior to the
>training, even if there is a significant difference post-training, it's
>not possible to tell whether the difference is the result of the training
>or was there to begin with.
The volunteers were assigned to the two groups randomly. This design
can in principal determine that the training causes a change, if other
aspects are done well. In particular, with a large enough sample, the
average pre-training confidence should be close to the same for the
two groups.
Of course, five subjects per group is rather few. Plus it's effectively
a non-blinded study. Subjects are likely to think (even if not told)
that self-defense training should lead to high self-confidence, making
any apparent difference suspect. Administering a test to measure
self-confidence beforehand would make this problem worse.
Radford Neal
