The general principles presented in the book, The Essential Guide to User Interface Design, are aimed to provide the best practices in order to design user interfaces for GUI or Web (Galitz 2007). Five of the general principles are Accessibility, Aesthetically Pleasing, Clarity, Forgiveness, and Directness (Galitz 2007).
This principle says that the system should be usable and accessible for everybody including people with physical incapacities (Galitz 2007). Moreover, by making the system more accessible, it increases the productivity of users that do not have disabilities (Galitz 2007). For example, a website designed and developed using the proper HTML elements and attributes and taking in consideration text based browsers like Lynx2, would benefit regulars users because.
Aesthetically Pleasing is the use of graphic design principles to create a more appealing user interface (Galitz 2007). This principle is more related to the attraction of the users to the beauty which improves productivity in long term (Galitz 2007). For example, the author points out “a lack of visually pleasing composition is disorienting, obscures the intent and meaning, and slow down and confuses the users” (Galitz 2007). A good example is the use of proper whitespace between elements to create a sense of relation between them. If the elements are close, they are related, and if they are far it means they are not related. We can see this example in toolbars where copy and paste buttons are next to each other.
This means that the interface should be visually pleasant for the users from visual elements to text (Galitz 2007). The elements used in the interface should not allow ambiguous messages to the users. An example is the clarity is the use of a wastebasket for deleted files because the concept behind relates a lot with the real world.
As users usually make mistakes while using a particular system, the application should provide a level of “forgiveness” and prevent the users to make mistakes (Galitz 2007). A very good example is the textbox requiring a phone number where the user should be allowed to enter the phone number in any format: “999-999-9999”, “(999)999-999” or 999999999. The system should be the responsible for gives a proper format to the data. In case this is not possible, then the system should provide some type of hint to help to enter the data in the right format.
This principle states that the system should provide direct ways to accomplish a task (Galitz 2007). In addition, it should provide alternatives to reduce the user’s mental workload (Galitz 2007).