If someone asked me to explain web usability in the simplest and most efficient terms, I’d fall back on the VIMM Model.
What is the VIMM Model?
VIMM describes the four ways we make users work too hard. It stands for Visual, Intellectual, Memory and Motor. Once you understand these four simple concepts, you can account for 80% of usability issues.
Visual Clutter
Visual clutter creates difficulty in finding things. It’s caused by:
- Too much content on the page
- Haphazard page layout
- Screen flows that don’t match task flows
- Bad alignment or formatting of text
- Too many calls to action
- Harsh or clashing colors
Hint: Make it easier by:
- Designing to a carefully designed grid
- Eliminating unnecessary elements
- Carefully aligning and formatting text
- Using color judiciously
Intellectual Complexity
This is where we make users figure things out, for example with:
- Confusing navigation titles
- Overly complex work processes
- Unclear instructions due to poor copywriting
Hint: Make it easier for users by:
- Providing previews
- Using everyday language, eliminating jargon
- Ensuring controls function consistently
- Providing good feedback
Memory Load
We tax the user’s memory load when we force them to remember things:
- Usernames and passwords
- Hiding important functions in menus and behind tabs
- Workflows that – although intellectually simple – are so convoluted that users forget where they are in the process.
Hint: Allow users to rely on recognition rather than recall:
- Provide clear navigational feedback
- Ensure options are visible
- Provide sensible defaults
Motor Load
This is where we demand too many – or overly precise – physical movements. For example:
- Excessive clicking and typing
- Device switching (e.g. keyboard/mouse)
- Excessive scrolling (especially horizontally)
- Presenting small, hard to hit targets
- Large distances between targets
Hint: Make it easier by
- Simplifying task flows
- Providing short distances and large targets
- Optimizing for the input device
- Allowing common keyboard shortcuts
So there you have it. A clear, easy way to think about usability and addressing usability issues.
