First 3 design principles here were written by Andrew Vizmuller
The Structure Principle – This refers to the architecture of the layout, where everything is organized with purpose. Information and objects that have similarities should be grouped together and they should visually look alike. An example of good structure can be found in Photoshop’s toolbar:
Here we can see that clicking on a tool yields consistent results. You either get the tool you clicked on, or if there is a small triangle on the image, holding the mouse down will pop-up additional options. The tools are worded effectively so that users can have an understanding of it’s function, along with a small descriptive icon. Finally, similar tools are grouped effectively together under the same sub-menus (see picture for example).
The Simplicity Principle – Ensure that the interface is easy to understand and navigate. Tasks that are repetitive should be easy to execute and even hot-keys can be used to speed things up. An example of simplicity can be found in Notepad:
When users want access to software, they don’t necessarily want the most elaborate up-to-date software with all the bells-and-whistles that come with it. Sometimes a plain and simple text program is all the user really wants to jot down a quick idea, and not a word processing program with hundreds of options – so, look at other applications with a grain of salt. Your design should be intuitable, a large, blank text screen makes it obvious where to start typing and a brief menu-bar is easy to understand. Also don’t create busy user interfaces, a key to making a program easy and enjoyable to use is to take away confusion and complexity.
The Visibility Principle – The task that users want to accomplish should be clearly visible and not confused with unnecessary information. Make sure that the user is not being overwhelmed and eliminate redundant options. An example of this is in Skype:
On the left hand side of the screen there is a list of contacts and after one of them is selected, then more details and options are provided about that contact. This must be easy for users to understand, so navigation within a screen is important. Make sure to use colour appropriately, in this case the Call button is prominently displayed in green to grab the user’s attention. However when using colour, follow the contrast rule and make sure that light colours are on-top of a dark background and vice versa to make sure that the text can still pop-out and be readable.
The Feedback Principle Following the feedback principle user must be getting feedback from the user interface. If user does an action, and doesn’t see the result or is not notified, then he/she doesn’t know if the action was done.
(Use color appropriately, Word your messages and labels effectively , Your design should be intuitable)
In this example Windows asks me if I really want to delete all of my work done for my DMA classes. This is a good example because it notifies user of the action that is going to be done, and also protects user from losing all of his data.
The Tolerance Principle
Design and functioning of the user interface must be done in the way that user will be guided to certain features, and prevented from using others. Also user should have an ability to recover his actions.
(Expect your users to make mistakes, Your design should be intuitable, Word your messages and labels effectively )
In this example Photoshop allows doing certain actions, and it doesn’t allow others that will lead to an error.
The Reuse Principle
Functioning of the user interface should be consistent to prevent user from rethinking and remembering how each part of the interface works.
(Set standards, Consistency, Look at other applications with a grain of salt)
This example shows different user interfaces, but in all of them functions responsible for window minimization, maximization and closing are located in the top right corner.
