Vicarious learning allows an observer to improve his decision making and modify his actions through observing others' past actions and resulting consequences. As organizations become larger and more disconnected, it becomes an increasing challenge to meaningfully share lessons learned allowing people to learn vicariously from both good and adverse experiences of others. In an effort to promote vicarious learning across disconnected groups, organizations create lessons learned programs to share information. The goal of a lessons learned program is to improve organizational effectiveness by avoiding costly errors “before” reoccurring in other parts of the organization. This type of antecedent learning requires collaboration between the people at the source and those receiving the lesson, as well as any human intermediaries involved with the process, to amplify the benefits of lessons learned. This paper makes explicit the connection between vicarious learning and collaborative lessons learned programs and develops a lessons learned process model using the theory of knowledge creation. The evaluation of four case studies reveals that a lessons learned program operates most effectively when the information is targeted to recipients who would find it useful and when human collaboration is acknowledged and supported by intermediaries.

This study investigated usability of graphical icons in the design of human-computer interfaces. A simple additive model of icon acquisition time, including terms for Index of Difficulty, mode of icon array, and log2 (number of icons) explained 95% of the variance in mean times covering all 36 conditions over 4 laboratory experiments conducted in the study. The acquisition of icons in graphical menus was subject to Fitts' Law. Where the dialog box only appeared on the screen when an action was initiated, acquisition time included a choice time that was additive with movement time. When a choice was required during the task in addition to a movement, both the number of icons and their configuration affected the choice time. Design implications are that the number of icons should be minimized in pop-up menus and that the icons should be arranged in a manner reflective of the shape of the useful field of view. Frequently used menus or icon arrays should be permanently visible to minimize performance time (e.g., by using task bars to hold common icons). Dialogue windows, especially with a larger number of icons, should be built in compact, perhaps square, configurations. If it is not possible to use a square icon configuration, it is desirable to use a horizontal configuration, which can be utilized more efficiently than the vertical configuration

The visual search process is modeled as a sequence of fixations which may or may not partially overlap in coverage of the search field. A single expression is derived for the probability of search success which covers all overlap cases. Making the further assumption that search strategy is chosen so as to maximize expected value, yields the result that each point on the search field must be fixated an integral number of times. In an experiment where visual lobe size and fixation duration were controlled, human subjects behaved in a manner close to that predicted by the optimization model. It is concluded that further development of the model using less restrictive assumptions is warranted.

An earlier paper by the authors (see ibid., vol.SMC-17, no.3, p.455-64, May/Jun. 1987) described an optimization model of self-paced tracking that could mimic human performance on linear courses. In the present paper, it has been extended to cover circular courses. The literature shows that as the curvature of the track increases (smaller radius) so the performance decreases. The model was able to predict this effect, both from the literature and from an experiment performed using six subjects. The absolute magnitudes of the speeds and error rates were predicted accurately by the model, as were the effects of track width. However, the model predictions underestimated the size of the radius effect somewhat, probably due to the specific biomechanics of the experimental equipment.>

An optimization model of human motor control in a laterally constrained self-paced path control task (e. g., driving) is proposed. The model structures the task as intermittent control with Begg's relationship used to describe the growth of lateral error with distance traveled during the sampling interval. Rewards and penalties are explicitly present in the objective function to be optimized. The path geometry is used with nonlinear optimization to solve the model and show that it has the expected reactions to payoff changes. Tests of the model against existing data in the literature and directly against the data from laboratory subjects showed a very close correspondence in form and numerical values between the model's prediction and human subject's performance.