Homework 5, Geng Zhou(gz2154)
Domain chosen: UI design--rapid, incremental, reversible operation
Paper 1: Direct manipulation for comprehensible, predictable and controllable user interfaces
In this paper, the author summarized the experience of using direct manipulation in the past few years before the paper was written. As to the users, direct manipulation systems give many positive feelings such as mastery of the interface, enjoyment in using the system and competence in performing tasks.
By comparison, the author also pointed out the two key reasons for users to choose direct manipulation systems rather than using intelligent agents:
1. By adopting direct manipulation rather than an agent to do the work for users, a user will have the feeling of full control over the system so that they won't feel anxious. On the other hand leaving the jobs to agents give users a worry that the system is unpredictable.
2. Responsibility issue. When there is something wrong with a direct manipulation system, it is very easy to know whose responsibility is it. However, for a system that uses intelligent agents to do the work; it is hard to say whether it is the agents that goes wrong or the user who give input to the agents.
Paper 2: "Sparks of innovation in human-computer interaction", Chaper 1.1 Direct manipulation: a step beyond programming languages
In this paper, the author explained the meaning of direct manipulation:
1. Visibility of object of interest
2. Rapid, reversible, incremental actions
3. Replacement of complex command language syntax by direct manipulation of the object of interest
Examples are also illustrated to show the effectiveness of direct manipulation. The examples include display editors, video game and CAD. Graphics representation is considered to be "especially helpful when there are multiple relationships among objects and when the representation is more compact than the detailed object".
However, there is also a problem with the direct manipulation: it doesn't necessarily improve performance.
According to the theory and practice stated the two papers, in the interface design of my project, I should not try to use agents but to give the user a very direct control of the syste--I should keep the transformation of the result clear and simple, and more importantly, the interface should react to the userí»s behavior without any delay (e.g. if a user points to an icon, a picture of the structure should pop out at once and same for other options). Also I will make the icons that the users can operate on (e.g. drag the icons to other places) seem like real physical objects so that the user can understand it quickly.