Is it appropriate or wise to merge two similar search inputs together?

Question

I have an application team that is building a simple search component in which there are two fields. Both accept a number only value that represents primary keys in two different tables. Would it be better for these fields to be combined from a usability point of view or should we keep them separate? Are there benefits in keeping them separate as show below?

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Additional Information:

No matter what the user enters, in either field, the same table is presented to them. The user can not fill in both inputs at the same time.

For more clarification, this is a task system. The first input box is for users to enter in a number (up to 9 digits) that represent a specific or set of tasks (i.e. all task starting with 100*, or the task with the number 123456789). The second input lets the user search for all tasks related to a specific customer number. For the second input the user must enter the full number.

Answer 1

As I understand, the user knows what he’s searching. So the user has to deside if it’s a task-search or a user-search.

• If the system is able to decide whether the input is a task-number or a customer-number one field would be better because the user would not be forced to decide. In the case, that there are hits on customers and on tasks you could ask the user witch of the two should be shown in the result list. If this happens often, the asking would be annoying. But if this happens only sometimes, this could be a possibility.
• If it’s not possible to let the system decide you could show one search-field and show two buttons “search user” and “search task”. Advantage: Since there is just one inputfield, the focus is always on the right spot. The user can just start to type without to worry if it’s in the right inputfield. With two fields, there’s always the possibility, that the user types in the wrong field and it’s cumbersome to type the number again into the other field.

Answer 2

If the system can determine if the data is a Identity1 or Identity2, I recommend you to have only one field and only one submit button, and add a label (or placeholder) to explain that you can give a Identity1 or Identity2.

For example, assume that Identity1 is a name and Identity2 is an address, you can have :

More generally you can have something like that for Identity1, Identity2, ... IdentityN :

The only thing is to be able to recognize the identity of a data. If you can't, it's also possible to search in all Identities the presence of the data.

Answer 3

Do both fields behave differently or are the exactly the same but the user will want to put in multiple search items? If the user just wants to add multiple search criteria you could use an input with that accepts multiple inputs like Select 2.

Answer 4

Can you first tell us on what grounds you decided what the future users of the interface with those search boxes will need?

As you know, we are here to design for users, but you said that your team is more convinced by one or the other solution.

I'm quite sure that you should test it with users of this specific industry. It's not a common scenario and we don't know enough about their preferences and the context to decide for them. People who work with such an interface are already used to certain kinds of usability and design, so you should ask them!