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Many thanks!

Just one last question here, I did not code specifically to include interactions, as my understanding is this will increase the S-estimates? But does Ngene automatically assume any interactions unless I specify?

Regards

Hi Michiel,

Thanks so much for your advice! It does seem like our priors from our pilot study are influencing the large S-estimate number. I have been playing around with the number of Bayesian priors and found that if I reduce the number it lowers the S-estimate, so perhaps not all priors should ...

Thanks Michiel!

Are you looking at the s estimates for each individual parameter, not the overall S-estimate? Maybe I am misinterpreting the values and how to assume a sample size from these numbers? I thought we calculated the overall S-estimate by the number of blocks to get the total sample size ...

Hi Michiel!

I was hoping you may be able to help me with my S-estimate/sample size in Ngene. I have obtained priors from STATA output from a pilot study of 21 respondents. I used the coefficient values, where if the coefficient was .5678 I would write the prior as 0.6 in the output below:

Design ...

Sorry Just one more thing!

it just occurred to me how do I know which alternative is the reference when interpreting the output? I realise we have no output with Zero priors at this stage, but when coding for the Bayesian D-efficient design will the opt out be the reference?

Thanks Michiel! again very helpful

Hi Michiel,

Your responses have been very helpful! it is such a relief to be able to clarify questions with you on this forum.

Just in regards to question 2, apologies for not being clearer but what I meant was when we set up the survey we wanted to alternate option A (opioid) and option B ...

Hi there,

I have designed a DCE with the following syntax and have a few questions before I use this to run a pilot study:

Design
;alts = alt1, alt2, alt3
;rows = 60
;require:
alt1.LBP = alt2.LBP ,
alt1.Comm = alt2.Comm
;eff = (mnl,d,mean)
;block = 5, minmax, noimprov(10 secs)
;alg=mfederov ...

Hi There,

I am a bit confused as to how to interpret the S-estimate and could not find clear directions in the manual. Basically I ran my code and got an S-estimate (for the Bayesian Mean) of 7.10 (it is 4.2 fixed). I have 5 blocks so I assumed to get the sample size I multiply the S-estimate by ...

Hi,

Just a quick question, I am noticing now that sometimes when I run the exact same design a second or third time, after closing and then reopening Ngene, I get a different D-error and S-estimate (all scores are different but these are what I look at most at this stage). I am just wondering is ...