Throughout the years, I've noticed several recurring misuses of terms in user interfaces. Designers or developers often don't know when to use one term over another, or what the difference between two similar terms is. These really are grammar rules, but they specifically apply to user interfaces.
As a general rule, if there is a term with two words and another term with those two words written as one word, the former is considered a verb and the latter is considered a noun.
Log In vs. Login
Log In: (verb) To authenticate or provide an identity to a website, app, or service.
Katie logged in to Facebook.
Login: (noun) 1. One's credentials or identity for a website, app, or service. 2. The specific page, section, or feature that provides functionality for logging in.
- Katie provided her login to Facebook.
- Katie visited the login page.
- It's best to avoid using login for credentials as it can be confusing to users. Instead, specifying "username and password" or similar required credentials is more explicit.
- Login can be useful when referring to pages internally, but should be avoided in user-facing text in favor of the action verb log in.
...and Log On
Log On: (verb) 1. Usually synonymous with log in. 2. Informal: to visit a website.
- Log on to the computer.
- Log on to www.example.com to see our latest posts.
- It's best to avoid this one as well since log in is more common.
- A better term would be "visit."
Sign In: (verb) Synonymous with log in.
Katie signed in to Facebook.
Using sign in versus log in is a preference. However, be sure to use only one of the terms, and use it consistently.
Log Out and Sign Out
Log Out: (verb) 1. The opposite of log in. To deauthenticate from a website, app, or service. 2. Informal: to leave or close a website, app, or service.
- Katie logged out of Facebook so her sister could log in.
- Katie logged out of the website by closing the window.
- Logging out should be an explicit action.
- Although log out is commonly used this way informally (especially by those who are less computer literate), it's best to avoid it.
Sign Out: (verb) Synonymous with log out.
Always use the parallel verb for your log in or sign in.
Set Up vs. Setup
Set Up: (verb) To prepare or initiate.
Katie set up the computer for her sister.
Setup: (noun) The process that involves preparing or initiating.
Katie performed the setup of the computer.
Less vs. Fewer
Less: a smaller amount when the item is not countable.
Katie has less hair than her sister.
Fewer: a smaller amount when the item is countable.
Katie has fewer hairbrushes than her sister.
If the subject you're comparing is not commonly referred to as a countable quantity of individual items, i.e. lots of sand, use less.
If it is commonly referred to as a countable quantity of individual items, i.e. three grains of sand, use fewer.
If you're unsure, ask yourself, "Is it how much or how many?" Much = less, many = fewer.
Are there other terms you've seen misused in user interfaces? Let me know in the comments.