The objectives of this research were to study the effects of:
(i) information load (pieces), and
(ii) information load (bits),
on decision quality and decision confidence in two decision-making tasks (a structured and an unstructured decision-making task). Since load effects were likely to be mediated by other variables, information load was studied in conjunction with three other independent variables:
(i) information diversity,
(ii) decision-task learning, and
(iii) decision-making experience.
In this research, decision quality was operationalized as:
(i) decision accuracy in the structured task and profit in the unstructured task, and
(ii) decision time (note, this variable is inversely related to decision quality., i.e., the lower the time the higher the decision quality).
It was hypothesized that information load (pieces), information load (bits) and information diversity would have similar effects on decision quality; namely, if load (pieces), load (bits), or diversity were plotted on the X axis and decision quality on the Y axis, an inverted U curve should result. The initial rise in the curve (the boredom effect) did not occur in the results and requires investigation in future research. The remainder of the curve was largely supported by the results. There were exceptions, however, that require further investigation in future research.
It was hypothesized that decision-task learning and decision-making experience should also have similar effects on decision quality; namely, higher learning or experience should result in higher decision quality. This hypothesis was largely supported by the results, expecially in the case of learning. Again there were exceptions that require clarification.
In the decision-quality results, there were three interaction effects that occurred more than once. These were:
(i) if load (bits), load (pieces), diversity, or experience had an effect on decision quality, the effect tended to be reduced by increased learning,
(ii) load (pieces) plus diversity effects were greater than additive, and
(iii) experience effects on decision accuracy and profit tended to be greater at lower loads/diversity and, to a lesser extent, the reverse was true for decision time.
These effects did not occur in every case possible, however, and consequently, further research is necessary.
In the decision confidence results, the load (bits) and learning effects were as hypothesized; namely, higher bit loads resulted in lower decision confidence, and higher learning resulted in higher decision confidence. Load (pieces) and diversity had no effect on decision confidence and the
effects of experience were mixed. Future research should study further the effects of load (pieces), diversity and experience on decision confidence.
Regarding future research, this research shows the importance of the task learning variable. Not only has this variable had main effects on all three dependent variables, but in addition, it has interacted with other independent variables. It consequently seems important that learning be included as a controlled variable in all research of this nature. This research also shows that inexperienced decision makers are not good surrogates for experienced decision makers. Experience has had significant main effects on all dependent variables, and in addition, it has interacted with other independent variables.