Asking a user what they have and provide them a way to do it vs only providing them a way to do it

Question

I work for a company that provides survey software for large food companies for taste testing. They use our software in their labs to test new products or improve existing products. Sometimes they want to keep track of who does the tests (user login) sometimes it's an anonymous test and they have a code that the user will input to take them to the correct test

I have a login where the user can either put in a code and proceed anonymously, or they may already have a username/password.

Does it makes more sense to ask the user if they have a code, or just show them where to put the code in? (remove/change the red text).

Answer 1

It's unclear to me how the user is getting the code. Is it a special invitation, or can they ask for one? I am going to assume it's a special invitation in the following suggestion, because your UI doesn't have a place for the user to ask for a code.

Suggested UI / Interaction:

When you send the user the code, you can have a direct link for them to "log in with the code". That link would take them to a login page with the code field presented in the UI. You can still have a "log in with username and password" hyperlink underneath it somewhere for them to choose that option if they want to change their mind.

If someone is just going to your site, your default login page could be the username and password fields. You can have a hyperlink underneath it saying something like "Do you have a test code?" and if they click that it would take them to the same page as described above.

This approach would:

1. Defaulting to the most likely use case, but still the user to switch between the two options
2. Reduce confusion for users if they are unaware of what a "code" is
3. Clean up the interface because you'd only need one login option presented at a time