抄録
In our everyday activities, every single action does not always smoothly shift to the next one. This even holds true for a simple task such as preparing a cup of coffee or some foods, although such actions appear to be well organized at first glance. In fact, small corrections of movements called ‘microslips’ by Reed & Schoenherr (1992), and short pauses occur frequently at the boundary of successive actions. These ‘stutters’ of actions seem to be related to the variability of the paths and flexibility of human behavior for achieving the goal of one and the same task. The present study observed 29 participants preparing a cup of beverage and some foods, and investigated how microslips and pauses were related to the shifts of actions in the task. The analysis shows that microslips and short pauses occur much more frequently in the shift of movements at the boundary of successive sub-tasks than the shift of movements within a single sub-task. The high frequency of microslips and short pauses in the shift of successive sub-tasks, it is suggested, results from the decreasing number of constraints of the task and, hence, the increasing number of opportunities of movements to be selected in the environment in the shift of successive sub-tasks.
