[EMAIL PROTECTED] writes:
> In Indiana, the school accountability legislation calls
> for locally produced assesments to be used. An assessment is to
> be given to about 1600 students in the high school in which I
> teach. This assessment will be given each September and May
> starting with the 2003-2004 school year. How large of a sample must be
> drawn from this population in order to approximate the mean score
> for all of the students? Is it possible to determine the size of
> the sample if there is no baseline data for this population with
> regards to this particular assessment?
I can't really believe that you would give a test to 1600 students and then only grade a fraction of them. Wouldn't the students get upset about this? If I took a test, I would be very interested in finding out how I did.
You've already gotten some very good advice. If you are still intent on taking a sample, I have some general guidance on my web pages. Start at
http://www.childrens-mercy.org/stats/size.asp
and take a careful look at
http://www.childrens-mercy.org/stats/size/power.asp
http://www.childrens-mercy.org/stats/size/confid.asp
http://www.childrens-mercy.org/stats/size/population.asp
among the other links on this page. Some of these pages are not yet complete, but should give you enough guidance to get started.
If you've never given this assessment before or anything even close to it, it would make a lot of sense to run a pilot study. It goes well beyond estimating the sample size. There are so many things that could go wrong, and better to find out early with a few dozen students than to have the thing blow up on you with all 1600 students.
I have a web page on pilot testing at
http://www.childrens-mercy.org/stats/plan/pilot.asp
Best of luck!
Steve Simon, [EMAIL PROTECTED], Standard Disclaimer.
The STATS web page has moved to
http://www.childrens-mercy.org/stats
