Table of Contents Executive Summary 2

2.3.1 Best Practices in User Interface Design

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  The structure principle: Your design should organize the user interface purposefully, in meaningful and useful ways based on clear, consistent models that are apparent and recognizable to users, putting related things together and separating unrelated things, differentiating dissimilar things and making similar things resemble one another. The structure principle is concerned with your overall user interface architecture.
  

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  The simplicity principle: Your design should make simple, common tasks simple to do, communicating clearly and simply in the user’s own language, and providing good shortcuts that are meaningfully related to longer procedures.
  

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  The visibility principle: Your design should keep all needed options and materials for a given task visible without distracting the user with extraneous or redundant information. Good designs don’t overwhelm users with too many alternatives or confuse them with unneeded information.
  

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  The feedback principle: Your design should keep users informed of actions or interpretations, changes of state or condition, and errors or exceptions that are relevant and of interest to the user through clear, concise, and unambiguous language familiar to users.
  

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  The tolerance principle: Your design should be flexible and tolerant, reducing the cost of mistakes and misuse by allowing undoing and redoing, while also preventing errors wherever possible by tolerating varied inputs and sequences and by interpreting all reasonable actions reasonable.
  

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  The reuse principle: Your design should reuse internal and external components and behaviors, maintaining consistency with purpose rather than merely arbitrary consistency, thus reducing the need for users to rethink and remember.
  

Additionally, Ambysoft has compiled an additional list of tips and techniques to help develop a successful user interface:

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  Consistency: It is import that the user interface is consistent at every facet of the application. For example, if a menu item can be double clicked in one portion of the application it should have the same properties when appearing in another part of the application. Consistent color schemes, labeling, wording, and functionality all help the user build an accurate mental model of how the application should work and drastically lowers the learning curve when being introduced to a new application.
  

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  Navigation between major interface items: If it is difficult to navigate between the major areas of the applications, users are likely to get frustrated and give up. The flow between screens in the interface should correspond to the flow of the work that the user is trying to accomplish. User interface-flow diagrams like that shown in 2.3.1 Figure 1 below, are a good metric to understand how a application flows between its interfaces and for what reasons.
  

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  Effective message and label wording: Since the text displayed in the interface is the primary source of information for the users, it is important that it is properly and positively worded, avoids using code or jargon, and is again consistent. Positively worded messages, for example, would be something along the lines of, “An account number must consist of 8 digits,” as opposed to something along the lines of, “you have incorrectly entered your account number.”
  

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  Align fields effectively: When a screen has more than one editable field, it is more visually appealing and effective to have the fields aligned in such a way that facilitates their entry. This can be accomplished by simply having the left edge of all of the fields line up to the same points, grouping fields that hold similar information, having the fields label in a consistent location to the field.
  

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  Expect your users to make mistakes: The user interface should account for human error and should easily recover from errors that occur from a missed or incorrect input, or any other situation that may occur from a confused user or a slipped finger.
  

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  A good user interface should be intuitive: If a user does not know how to use a piece of software software, they should be able to determine how it works by making a series of educated guesses. Even when the guesses are wrong, the system should provide reasonable results from which the user can readily understand and ideally learn how to navigate the interface.
  

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  Don’t create busy user interfaces: Crowded screens are difficult to understand and, hence, are difficult to use. Experimental results show that the overall density of the screen should not exceed 40 percent, whereas local density within groupings should not exceed 62 percent.