User Interface Design Criterions

By Xah Lee. Date: . Last updated: .

Here's some of the critical elements in user interface design.

Bad Flat User Interface Design

These User Interfaces fails basic usability.

linux xfce x11 gui ThinIce Greybird 2016-07-16
bad GUI. Linux Xfce ThinIce Greybird 2016-07.
  • Difficult to tell which window is in front.
  • Difficult to tell which tab is current.
  • Difficult to tell which is button, which is not a button.
  • Difficult to tell button's on/off status.

Flat Design of Original X Window System, Bad

This is bad, but excusable, because back in 1980s, computer resources are limited. You can't draw 3D widgets or shadows.

X Window System 2007 04 22  11965
Appearance of the original X Window System, 1980s image source

Grey Slab Design of Classic X11, Not Very Good

In 1990s, unix X11 (including Linux) sports a grey slab style. This is better than flat, but still hard to discern the various states of buttons or boxes.

DECwindows openvms v7.3 1
DECwindows openvms v7.3 1, running on Solaris. (Year ~1998) Note the look of the scroll bar, the window border, and buttons. Why is it that way? because it's easy, simple, computationally less intensive, to write program to draw them that way and still get a 3D effect.
Firefox Certificate Manager 2012-10-22
Firefox Certificate Manager 2012-10-22, using X11 1980's Grey drab slab style of Graphical User Interface.
xfce window manager gtk theme
xfce window manager GTK theme. Not good.

Microsoft Windows Metro Sucks

Windows_10_flat_UI_2020-11-09-s250
Metro Flat Design Sucks

Great User Interface Design

linux xfce x11 gui Adwaita Kokodi 2016-07-16
Good GUI. Linux Xfce Adwaita Kokodi 2016-07.

Linux Xfce Good Theme Choices

appearance that has good GUI widgets:

bad x11 slabs:

Window Manager theme that has easily distiungished front window title bar:

User Interface Design