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alternative-specific design w/ multivariable prohibitions

The design generator doesn't let me produce a 'shortcut' design with alternative-specific design checked and corresponding prohibitions in place when I add any other generic and 2/3/4or5-way prohibitions.

The error message refers me to ASD help documentation but I can't locate any guidance on how to include additional complex prohibitions into an ASD.

Would it be possible to generate a design w/o the ASD prohibitions and manually tweaking them into the csv, then importing the design again? Sure, I'd have to do more testing wrt level balance and general efficiency, but is there any more potential methodological issues that I'm missing? (other than what generally applies to the use of prohibitions)

Thanks for some thoughts and or guidance!
asked Jun 16 by alex.wendland Bronze (1,745 points)

1 Answer

0 votes
You could certainly try that, but in my experience if our designer is failing to come up with a viable design, it likely is the case that a viable design just isn't possible with the prohibitions you've specified.

I'd love to take a look at the specifics of your project and see if we can restructure the attributes to get around some of these prohibitions. Please contact our technical support team directly for further assistance. (support@sawtoothsoftware.com)
answered Jun 16 by Aaron Hill Silver Sawtooth Software, Inc. (7,535 points)
hi aaron
I just tried to email the zipped study file but "mx.google.com" has rejected my message. anywhere else I can try sending?
Hi Aaron

I tried reaching out to the 801 477 4700 number via skype just now without any luck, maybe too early for a Monday :)

First of all, your email responses are very much appreciated and I understand that "+x on top of base price" attribute will resolve the need for some of the prohibitions. Either way I'm convinced that I'll still need some "hairy" prohibitions though, no matter how clever I reshuffle and tie together my attributes.

So maybe the quicker question to answer is this:
Prohibitions will generally hurt level balance and (worse case) to some extent independence, correct? Now that I've manually manipulated my design to match my requirements (i.e., ASD plus a lot of hairy prohibitions) AND that I've tested for statistical independence (confirmed), shouldn't I be fairly ok to move forward if
- importing back into Lighthouse was successful w/o issues
- main effects standard errors in testing are ~0.04
- observation counts are reassuring?
OR are there any inherent taboos or pitfalls in combining ASD with prohibitions? (i.e., it's gonna be bad, regardless of the test stats)

I just am taken aback that the design generator does not allow said combination (ASD + prohib.) as if it was not possible or inherently super detrimental.  You can reach me in Germany under +49 163 82 82 900 if there is more to the story than I just considered here. I take your tool's error messages very seriously but it contradicts my intuition here...