Developing the mechanism of recovery from error and user interface evaluation metrics, and proposing user model

所有的人都会犯错。您无法想象用户在计算机系统上工作时没有任何错误操作。因此，防止用户犯可预见的错误，并允许用户在错误发生时恢复工作，一直是人机交互的重要课题1。对于恢复操作，用户可能想要选择一个命令来撤消或重做，这称为基于命令的恢复操作；用户也可能希望通过撤消和重做来选择一个对象来恢复其状态，这称为基于对象的恢复操作。大多数撤消模型是基于命令的撤消模型，不允许基于对象的恢复操作。在本项目中，提出了两种撤消模型：基于对象的线性撤消模型和基于对象的非线性撤消模型。这两种撤消模式都可以支持基于对象的恢复操作。我们提出并开发了一种新的用户界面工具，用于直接选择撤消/重做机制。可视化历史对话框为用户提供了所见即所得的用户界面，使用户可以更高效地找到要撤消/重做的命令。呈现一组一个或多个特定对象的历史的能力将是下一代历史呈现中的有用特征。

All men make mistakes. You cannot image that the user works on a computer system without any mistake operation. Therefore, to prevent the user from making predictable mistakes and allow the user to recover his work when a mistake happens are always very important topics of human computer interaction.1. As for recovery operations, the user may want to select a command to undo or redo, this is called as command-based recovery operation ; the user may also want to select an object to recover its state by undo and redo, this is called as object-based recovery operation. Most undo models are command-based undo models and do not allow object-based recovery operation. In this project, two undo models are proposed : the object-based linear undo model and the object-based nonlinear undo model. Both undo models can support object-based recovery operation.2. We have proposed and developed a new user interface tool to the direct selective UNDO/REDO mechanism. The visualized history dialog box provides a WYSIWYG user interface to users so that the users can find out the command to be undone/redone in more efficient way. The ability to present the history of a set of one or more particular objects would be helpful feature in the future generation of history presentation.