Short answers below; which may or may not adequately address the lurking
questions you had in mind.
On Fri, 4 May 2001, Jeff wrote:
> Would like to ask [for] help with the following questions:
>
> 1. why designs for experiments should be orthogonal ?
So that results for each factor, and each interaction between factors,
will be mutually independent.
> 2. which problems may I encounter if I use non-orthogonal design ?
Same kinds of problems you encounter in the general multiple regression
situation: apparent size of effect of any predictor (or factor) will
depend on the presence or absence of other predictors in the model, and
also on the sequence in which the several predictors (factors and their
interactions) are considered in the statistical model.
-- DFB.
------------------------------------------------------------------------
Donald F. Burrill [EMAIL PROTECTED]
348 Hyde Hall, Plymouth State College, [EMAIL PROTECTED]
MSC #29, Plymouth, NH 03264 603-535-2597
184 Nashua Road, Bedford, NH 03110 603-472-3742
=================================================================
Instructions for joining and leaving this list and remarks about
the problem of INAPPROPRIATE MESSAGES are available at
http://jse.stat.ncsu.edu/
=================================================================
