Is it better/less confusing to show the user a longer list of options with some disabled, or only show the available choices?

Question

This is regarding a signup/scheduling request form:

In my business (appliance repairs), there are multiple manufacturers and products:

• Refrigerators
• Washers
• Dryers
• Microwaves
• Stoves

We don't work on all products for all manufacturers, so if someone picks "Samsung" for example, the list would be:

• Washers
• Dryers
• Microwaves
• Stoves

because we don't work on Samsung Refrigerators. If someone picks "Viking" the list would be:

• Microwaves
• Stoves

Because viking doesn't make washers and dryers and we don't work on built-in refrigerators.

I'm on the fence whether to show the entire list (about a dozen items) and draw a line though and disable the unavailable choices, or to simply not show the unavailable choices.

This: Don't hide or disable menu items? seems even more confusing than the other two options since it suggests giving an explanation as to "why?".

Customers don't really care why we don't work on Samsung refrigerators, all that matters is that we don't work on them.

Hiding the unavailable options seems like it would be a little confusing for the user because we fix refrigerators and they have a broken Samsung refrigerator, but showing the option and making it unavailable seems worse.

Does anybody have any ideas? Anything better?

Thanks!

Terry

Update:

I did some user testing and they all like

• Fewer options that are all valid

instead of

• All options with the impossible options disabled

UPDATE 2022-01-01:

I went with "Fewer options that are all valid".

The users see a list of brands we service. Once the brand is selected they're shown the products that we service for that brand.

Until the brand is selected, the product list is empty.

This has been well received by the customers and nobody has complained that it was difficult.

It's also cut down on people selecting manufacturer:product combinations that we don't service, as well as combinations that are impossible.

Answer 1

I can think of two approaches you might try:

1. Use a Filter. Show all of the options that the business can do, and then let the user filter by brand. Hide the unavailable options rather than showing disabled - a disabled state implies that the user or system can do something that might enable them somehow, and this isn't the case.

2. Use Progressive Disclosure. Before showing any options, have the user select their brand first, then show the list.

The better option is going to depend on why the user is on your page. Are they trying to book an appointment and just need to complete that one task (this sounds like the case)? Progressive Disclosure will help them stay focused. Are they generally looking at what your company does in order to decide whether you're a reliable business for many future needs? It might be better to start with the big list and let the user engage filters several times.