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Price Constraints in DOE

I am using Sawtooth Software SSI Web to create a Design of Experiment.
I want to know how can I add pricing constraints based on an Attribute.

For instance, amongst my attributes, I have Size Attribute and a Price_Size Attribute.

I want to add a constraint such that in a task, between two concepts, the 10ml sized concept is priced lower than the 20ml, 30ml, 40ml sized concept.

Is it within the scope of the software? If yes, can you kindly help me understand how I can proceed? Any reading material would be helpful.

asked Jul 20, 2021 by Chinmayi (225 points)

2 Answers

0 votes
Hi Chinmayi,

As per my understanding, you wish to apply a constraint such that the price visible with 10ml in concept 1 should be lower than another concept with 20ml.

This scope (inter-concept prohibition) is not covered in software by default. We have two ways of dealing with this scenario.

1. Create the design in an external package like R and then import in sawtooth to check efficiencies

2. Create a design with a large number of versions, identify screens that are not following our rule, remove them and import only cleaned sets.

I hope this helps.

answered Jul 20, 2021 by Saurabh Aggarwal Gold (34,895 points)
0 votes
Hi Chinmayi,

This is a great question for our support team as well. There are a couple of ways you can go about this. You can add a between-concept prohibition by clicking on the Prohibitions button in your CBC attributes tab. Then click on the Advanced Prohibitions tab. You can technically enter the prohibitions in the tab here by hand using the numbered attributes and levels that you do not want to appear together. I like to use the Add Prohibition button to help me out.

Click on the Between-Concept radio button and enter how many concepts you want to prohibit in a certain scenario. You do not need to select a level for each attribute. Depending what version of the software you are using, alternative-specific designs may not work in this window. If you have a lot of combinations between size and price, you can also set this up in Excel and paste the prohibitions in the table view.

Do all of your prices and sizes appear together? I always recommend testing the CBC design before fielding. Between concept prohibitions are not the most harmful type of prohibition but a lot of prohibitions can still hurt the efficiency of your design. If you have different pricing tiers for the sizes, you can consider using conditional pricing  (http://www.sawtoothsoftware.com/help/lighthouse-studio/manual/index.html?hid_web_cbc_cp.html). Feel free to contact our support team at support@sawtoothsoftware.com if you have additional questions.

Best Regards,

answered Jul 20, 2021 by Christina Miller Bronze Sawtooth Software, Inc. (2,225 points)