margin of error

[dennis roberts]

while there is lots and lots of discussion on lists like this for testing hypotheses ... and, we have been having a new flurry of discussions about confidence intervals ... what we hardly EVER talk about is the concept of "margin of error" ... that is, trying to PRE plan our accuracy (that is, have our sample statistic be within m of the parameter ... ) through the control of sample size n

why is this?

it seems that the margin of error idea is so practical and useful ...

trying to distinguish between confidence level AND accuracy or precision of your estimates is not that easy to achieve with intro students but, is it not worth the effort?

_________________________________________________________
dennis roberts, educational psychology, penn state university
208 cedar, AC 8148632401, mailto:[EMAIL PROTECTED]
http://roberts.ed.psu.edu/users/droberts/drober~1.htm

.
.
=================================================================
Instructions for joining and leaving this list, remarks about the
problem of INAPPROPRIATE MESSAGES, and archives are available at:
. http://jse.stat.ncsu.edu/ .
=================================================================