choice-metrics.com

Dear Michiel Blimer,
I have run the syntax for around 8 hours by

Code: Select all

Design
;alts=alt1*,alt2*,alt3
;rows=24
;block=2
;eff=(mnl,d,mean)
; con
;model:
U(alt1)=b0[(n,1.007,0.563)]+b1.dummy [ (n,0.161,0.263) | (n,0.032,0.299)|(n,-0.002,0.317)|(n,0.184,0.228)|(n,-0.206,0.292)] * locate[5,4,3,2,1,0]+b2.dummy[(n,0.334,0.189)|(n,0.103,0.214)|(n,0.187,0.256)] * pretest[3,2,1,0]+b3.dummy [(n,-0.098,0.228)|(n,-0.012,0.172)|(n,0.017,0.1779)] * posttest[3,2,1,0]+b4.dummy[(n,0.068,0.14)] *anonym [1,0]+ b5.dummy[(n,0.107,0.174)] *method[1,0]+b6[(n,-0.001,0.0003467)]*price[0,100,300,700]/
U(alt2)=b0+b1*locate+b2* pretest+b3* posttest+b4*anonym+ b5.dummy *method+b6*price
$

and the prior with s.e. from a pilot study. The d-error was 0.2089, however, the sp-estimate was a very large number. Could I improve my design more?
Sincerely yours,
Sukunta Muadthong

Based on the means of your priors, the sample size estimates indicate that:
- ASC should be easy to estimate
- Pretest dummy coefficients may require a few hundred respondent for most of them, but some categories have very small coefficients and may not be statistically significant if the priors turn out to be true
- Posttest dummy coefficients may require a few hundreds respondents and do not seem a worry
- Anonym coefficients seem to indicate that this attribute is not very important, so this attribute may not come out as statistically significant, which could also be a result, not everything needs to be important in decision making
- Method dummy coefficients may require a few hundreds respondents and do not seem a worry
- Price coefficient should be easy to estimate

Given that there is a large amount of uncertainty about the priors, you should treat some of the sample size estimates as only a best guess but could be very different. I do not see any major issue, I think that the sample size estimates look what they typically look like. There is nothing else you can do to improve them.

Michiel

Dear Prof.Bliemer,
Thank you so much for your recommendation.
Sincerely yours,
Sukunta