Question

When validating an IP address, what is the correct name of each dot seperated “part”.

For example, if a user inputs the following invalid IP:

999.45.34.23

What is the correct validation error message?

Is it: “The first IP octet is invalid” ?

References: wikipedia

Answer 1

I think you should stick with the technically correct term, which is octet.

The drawback, as others have observed, this has the potential to confuse typical users, who might have no idea what an “octet” is. Using a different term isn’t a good option either, though, because you’re likely to confuse and/or disappoint users who do know what an octet is and expected to see the correct term used in the appropriate context.

Perhaps the best compromise is daring to go beyond the typical “Error: Invalid input” style message. I would include a specific example of the input that was incorrect, along with the error text. In this case, you might show the IP address that the user entered, with the incorrect octet highlighted in red.

It requires a considerably greater amount of effort on the part of the programmer, who can no longer throw in a call to the MessageBox function and leave it at that. But there’s a huge gain in usability. The advantage of this approach is that an experienced user can simply read the textual message and know exactly what needs to be fixed. An inexperienced user who doesn’t understand the error can spend more time reading the dialog and still know exactly what needs to be fixed.

Consider the following concept sketch:

     

(Obviously, you’ll need to modify accordingly when your application finally decides to support IPv6.)