These are ten general principles for user interface design, from Jakob Nielsen. Keep it in mind while testing usability (or print it to keep it on your desk) and it will help you a lot.
- Visibility of system status
- Match between system and the real world
- User control and freedom
- Consistency and standards
- Error prevention
- Recognition rather than recall
- Flexibility and efficiency of use
- Aesthetic and minimalist design
- Help users recognize, diagnose, and recover from errors
- Help and documentation
Android Guidelines and Tips
Touch
- Sidebars are not easy to use on touchscreens.
- Fingerprints are more visible on darker backgrounds.
- There must be a way to go back or undo an action, as touching the wrong item is done quickly.
- The full screen should be used.
- Common operations directly visible on screen.
- Minimize keyboard input.
Icons & Buttons
- Buttons should have the right size and be suitable to big fingers.
- Buttons in the same place of the screen to avoid confusion.
- Natural and consistent icons.
- Buttons that have the same function should have the same color.
Menu
- Contextual menus are used very often, it should not be overloaded because it has to be used quickly.
Text
- Keep text simple and clear.
- Short sentences and paragraphs are better readable.
- The usage of headers will make a text better readable.
- Bullets for lists will make a tekst better readable.
- Typing text in a textbox should start with an uppercase letter.
- The font size should be big enought, not too big and not too small.
Messages
- Confirmation messages should be avoided, a click performs the action directly.
- When the app starts downloading a lot of data, the user should be warned.
“If the point of contact between the product and the people becomes a point of friction, then the industrial designer has failed. If, on the other hand, people are made safer, more comfortable, more eager to purchase, more efficient -or just plain happier- the designer has succeeded.”
“Photo Booth is a digital toy. The first version of Photo Booth, however clean and functional, did not look like a toy. It wasn’t fun, and it didn’t encourage you to play around with it. In the new fullscreen mode, Apple uses skeuomorphism to invite users to play.
Skeuomorphism is about communcating and reinforcing feelings – getting an application to become a memorable experience, not just a tool. It’s about communicating the purpose of a UI, not only the functions it enables.
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“The only thing we can fully control is how we set up the experiment, and so I judge a test based on criteria like:
Did we have clear segmentation of visitors into distinct variations?
Did we have clear, measurable, quantitative outcomes linked to those segments?
Did we determine our sample size using appropriate standards before we started running the test, and run the test as planned, not succumbing to a testing tool’s biased measure of significance?
Can we run the test again and reproduce the results? Did we?This might sound a lot like the way a chemist evaluates an experiment about a new drug, and that’s not by accident. The way I look at running an A/B test is much the same as I did when I was working in that lab: if you run well-designed, carefully implemented experiments, the rest will take care of itself eventually.
You might hit paydirt this time, or it might take 100 more tests, but all that matters is that you keep trying carefully. I evaluate the success of our overall A/B testing regimen based on whether it improves our overall performance, but not individual tests; individual tests are just one step along what we know will be a much longer road.
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I am, though, very interested in finding out why a game can keep people occupied for a long period of time, often without their even noticing that they’ve been sitting in front of the screen for hours. I want my apps and products to affect my visitors in the same way.
“Cada dólar gastado en UX reporta entre 2 y 100 dólares”