Line parallelism, graph memory and detecting statistical interactions

Abstract

Two types of line graph and one type of bar graph were compared in two experiments, requiring participants to answer integrated questions from memory. Questions were visual in nature and were related to the concept of statistical interaction. Both types of line graph contained the emergent feature of line parallelism, assumed to facilitate the task of detecting interactions. One type was unusual: it contained two separate, orthogonal value axes, instead of a single, integrated axis. In Experiment I, questions were relatively simple. Its results were fitted to a simple model of cognitive task execution. In Experiment II, the graphs were introduced as presenting the outcomes of an imaginary research study. In both experiments the line graphs resulted in superior performance, though memorising the unusual line graphs remained difficult, despite extensive pre-experimental training. The discussion focuses on the importance of graph-related and task-related variables in explaining performance on graph-based, memory-based tasks.

Keywords:

• emergent features
• graphical perception
• cognitive task analysis
• spatial memory