Show Details about an alternative specific constant with no attribute levels

Question

How can I configure the following in Lighthouse?

Primary attribute = Product: Decaf Coffee, Latte

Decaf Coffee Alternative Constant
Caffeine Content: Very Low
Flavor: Regular

Latte Alternative Constant
Caffeine Content: Moderate, High
Flavor: Vanilla, Caramel, Chai Tea

I thought about making the "Decaf Coffee" the none option. Ideally though, I'd like it's caffiene content and flavor to show up in the same row as the latte option during the task.

I tried making Coffee Caffeine Content and  Coffee Flavor as separate attributes from Latte Caffeine and Latte Flavor, but Lighthouse says every attribute has to have at least 2 levels.

Is there a good way to do this?

Answer 1

Not sure if you already figured this out, I had a similar question that I asked a couple days ago which I'm hoping to get similar clarification on. I can break down what I did for similar things that you're working on and what I think might be the right way to do it:

You have the primary attribute already (Product). For the two decaf options, because there's only one caffeine/flavor option, what I did was just make a second option with the same name (or you can add a space to the end of the second option if you get an error about duplicated names). So your attributes would be:

Product: Decaf Coffee, Latte
Coffee Caffeine Content: Very Low, Very Low
Coffee Flavor: Regular, Regular
Latte Caffeine Content: Moderate, High
Latte Flavor: Vanilla, Caramel, Chai Tea

Then under Merged Rows combine the two Caffeine Content options and the two Flavor options. When you go to do estimation later you'd just set it to ignore the coffee caffeine content and flavor options.

Answer 2

Usually these type of structures are handled by creating an alternative-specific design: https://www.sawtoothsoftware.com/help/lighthouse-studio/manual/index.html?hid_web_cbc_designs_7.html

In the example in that help page, it's kind of implied that walking or biking has no cost.  If we wanted to specifically call attention that there is no cost, you could add an additional attribute with two identical levels and then exclude it during analysis like Jacob mentions.  You'll have to do a little trickery because Lighthouse Studio won't let you have exactly the same labels for two levels (toss in a   space character or something will probably work).

It's probably easier to set up a conditional display table, though.  This will allow you to "fill in the blank" so when walk combines with missing (0 level) of price, the conditional display table could display the word "Free" instead of a blank.  But it's purely just a display thing, there is no "walk price" attribute and there is no "free" level in the design, it's just text displayed during the exercise.