R help - Sep 2012 - fractional balanced design conjoint analysis

L.S.

We would like to generate fractional design for a conjoint analysis. For example
we would like to reduce 2x2x2x2x3 --> 12-16 profiles. We tried the R-package
"conjoint" and we found an article which describes how to make
fractional design for these kinds of studies with Algdesign:

http://tolstoy.newcastle.edu.au/R/e10/help/att-8876/DCE_with_R.pdf
However, the generated fractional design can be quite unbalanced in the number
of levels for each attribute, probably because the fractional design is
constructed as orthogonal as possible. For estimating the main effects we would
prefer optimal designs in which the number of levels in each attribute is as
equal as possible.

Anyone has an idea how to construct such designs with R?

Thanks in advance!

Eric Boer
Food and Biobased Research
Wageningen UR
The Netherlands

	[[alternative HTML version deleted]]

> We would like to generate fractional design for a conjoint 
> analysis. For example we would like to reduce 2x2x2x2x3 --> 
> 12-16 profiles. 
package BHH2 includes routines for 2-level fractional factorials with specified
generators.
package FrF2 provides a different 2-level fractional factorial design toolkit.

Something tells me you won't get a balanced 2x2x2x2x3 fractional in 16 or
fewer runs though. I think 18 is possible.

S Ellison

*******************************************************************
This email and any attachments are confidential. Any use...{{dropped:8}}