User Experience Design and Usability Guidelines and Principles

This blog article is a collection of guidelines and principles for the practice of User Experience Design and Usability. 

Note: This is a work in-progress

• User Experience Honeycomb, by Peter Morville

1. Useful. As practitioners, we can’t be content to paint within the lines drawn by managers. We must have the courage and creativity to ask whether our products and systems are useful, and to apply our knowledge of craft + medium to define innovative solutions that are more useful.
2. Usable. Ease of use remains vital, and yet the interface-centered methods and perspectives of human-computer interaction do not address all dimensions of web design. In short, usability is necessary but not sufficient.
3. Desirable. Our quest for efficiency must be tempered by an appreciation for the power and value of image, identity, brand, and other elements of emotional design.
4. Findable. We must strive to design navigable web sites and locatable objects, so users can find what they need.
5. Accessible. Just as our buildings have elevators and ramps, our web sites should be accessible to people with disabilities (more than 10% of the population). Today, it’s good business and the ethical thing to do. Eventually, it will become the law.
6. Credible. Thanks to the Web Credibility Project, we’re beginning to understand the design elements that influence whether users trust and believe what we tell them.
7. Valuable. Our sites must deliver value to our sponsors. For non-profits, the user experience must advance the mission. With for-profits, it must contribute to the bottom line and improve customer satisfaction.

• 10 Usability Heuristics for User Interface Design, by Jakob Nielsen

1. Visibility of system status. The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
2. Match between system and the real world. The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
3. User control and freedom. Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.
4. Consistency and standards. Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.
5. Error prevention. Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.
6. Recognition rather than recall. Minimize the user's memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.
   (Read full article on recognition vs. recall in UX.)
7. Flexibility and efficiency of use. Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.
8. Aesthetic and minimalist design. Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.
9. Help users recognize, diagnose, and recover from errors. Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.
10. Help and documentation. Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

• Laws of usability, by Steve Krug 

1. Don't make me think
2. It doesn’t matter how many times I have to click, as long as each click is a mindless, unambiguous choice.
3. Omit needless words

• The Elements of User Experience by Jesse James Garrett

1. The original diagram that started it all 
2. The simple planes poster 
3. Chapter 2: Meet the Elements

 Note: This article is in-progress