The interactions of three factors that may be involved with the memory for pattern or sequence in visual materials were investigated in this study: (1) arbitrariness of representation; (2) task; and (3) ability of students. The subjects, who were 29 graduate students in education, were pretested for general ability and randomly assigned to four groups. Students studied a series of four maps which were arranged in order of increasing complexity from eight to 20 elements; these elements were shown either as pictures or as squares and were numbered from left to right and from top to bottom. The subjects were required to either list the elements in sequence or to draw the overall pattern. It was found that, although the scores generally declined as the number of elements increased, the results were significant for task (list or draw) and task by map (number of elements) interaction. A correlation was also found between one of the maps and the pretest. The implications of these findings for instructional design are that when seven or more elements are presented in maps, difficulties may result when students are asked to perform a successive task. On the other hand, when the task calls for simultaneous processing, access to a chunking strategy will enable students to compensate for the numerous elements. Supporting data for the study are presented in seven tables, and a list of 22 references is provided. (MES)