The well known quote from Alan Cooper is Conforming to the standard unless there is a better choice. There are some best practices in interaction design. How many do you know?
1. Fitts' Law
The time from one start point to target point is determined by two parameters: The distance to the target and the size of the target. )D and W in above picture), the formula is : T=a+blog2(D/W+1).
It was first proposed by Paul Fitts, it is mathematical model used to predict the time from any point to the target point. It has great influence in HCI and design field. The transform from Start Menu to Start Screen in Windows 8 is an application of Fitts' law.
Significance of Fitts' law:
- Clickable objects such as button should have a reasonable size
- Corners and edges are good place to place menubar and buttons, because edges and corners are huge targets. They are infinite high and wide, you cannot move beyond of them no matter you far you move your mouse.
2. Hick's Law
The more choices(n) there are, the longer it takes to make the decision(T). The mathematical formula is : T=a+blog2(n). So if there are too many choices in the interactive interface, the time spent will be longer. For example, there are two menus, each menu have 5 options will take longer than one menu with 10 options.
Hick's Law are frequently used in menu and submenu designs of software/website, it also works in mobile devices.
3. Magic number 7±2 theory
In 1956 George A. Miller did some quantitative research on short-term memory capacity, he found that the best state of the human mind to the memory containing 7 (± 2) information blocks, the human mind began to go wrong by memorizing out of 5-9 information blocks. Similar to Hick's Law, the magic number 7 ± 2 theory is often used in the design of interactive mobile applications, such as the number of tabs in an application is not more than 5.
4. The Law of Proximity
According to Gestalt psychology: when the objects are too close, we will think they are related. For example, a submit button will be next to a text box, so when the function blocks close to each other are not related, it means the interaction design may have some problems.
5. Tesler's Law
The Law of Conservation of Complexity: Every application must have an inherent amount of irreducible complexity. The only question is who will have to deal with it.
6. Error prevention principle
Error prevention principle says that the majority of accidents are caused by negligent design, rather than human negligence in operation. By changing the design, the faults can be minimized. This principle was first used in industrial management, but also applicable in interactive design. For example USB slot in hardware design; it is often seen in interface interaction design as well.
Conclusion
In order to comply with the magic number 7 rule, we only introduce a few laws here. If you are still interested in finding some other rules or laws such as Steering Law, Gutenberg Diagram rules as well as Pareto's Law (80/20 principle), trisection principles etc.
Although these rules are recognized as the standard by many people, a lot of people also remember Alan Cooper's quote, in reality these rules are only references to interactive designers
Original author : Afio Source : http://www.geekpark.net/read/view/166489
