Have an idea?

Visit Sawtooth Software Feedback to share your ideas on how we can improve our products.

CBC with Conditional Display

Dear All,

We got a project with 3 products A, B, C
Each  appears on market with its own specific number of clips.
Product A - always 1
Product B - always 10
Product C - 10 or 12 or 16 or 18

So we got 2 attributes Product and Number of clips, there are 3 other attributes but let's put them aside.
Attribute "Number of clips" contains 4 levels : 10/12/16/18
To avoid prohibitions I used conditional display where for Product A and each of level "Number of clips" appears always "1"
For product B and each level "Number of  clips" appears always "10". For  Product C - no conditions, it shows according to design  4 levels (10/12/16/18)
I didn't launch the study yet, just tested and looked at utilities.
So on individual level I received exp.  part-worth utilities for attribute "Number of clips":
Level     :    10       12        16        18
Utilities: -2,82   -0,28   2,64     0,46

My question is  - for simulation (share of preference) when I would like take into account Product A (with 1 clip) which level of clips I should consider ?
Maybe just ignore it and only consider utilities for Product A ?

All the best,
asked Jul 22, 2015 by robson Bronze (750 points)
edited Jul 29, 2015 by robson

1 Answer

0 votes
Hi, Robert.

Even before that, you don't have utilities for 1 clip (Product A) and the utility you get for 10 only applies to Product C, right?

I think you need to analyze this as what's called an alternative-specific design.  I'd show the task as you describe but in analysis I'd zero out variables denoting the number of clips for products A and B.  Then when you simulate them you needn't add a utility for number of clips at all (that utility is captured in the Product B and A brand constants).  You would then select N/A as your number of clips utility for products A and B.  

If I'm understanding your design properly, this should do the trick.
answered Jul 22, 2015 by Keith Chrzan Platinum Sawtooth Software, Inc. (84,975 points)
Thank you Keith !
This is what I suspected. For Products A and B just ignore Number of clips as these utilities are already captured in utilities for Product A and B.
All the best !
Your suspicion was a good one.  Good luck!