A qualitative evaluation of maptime, a program for exploring spatiotemporal point data

The purpose of this paper is twofold: (1) to provide a user evaluation of MapTime, a software package for exploring spatiotemporal data associated with point locations, and (2) to examine some cognitive issues associated with the display of a dynamic geographic phenomenon - the change in population for cities over time. The methodology consists of a combination of individual interviews and focus groups conducted for three distinct groups of participants: novices, geography students, and domain experts. Some of the key findings are (1) that people do not naturally think of time lines in association with time (clocks and calendars are more common), which raises questions about the use of a linear time line for controlling animations; (2) that pictographic symbols tend to be preferred over geometric symbols for static maps, but pictographic symbols are apt to be too complex for animated maps; (3) that animations, small multiples, and change maps all have important roles to play in examining spatiotemporal data - animations for examining general trends, small multiples for comparing arbitrary time periods, and change maps for explicitly depicting change; (4) that automatic animations are useful for examining trends in pattern, while user-controlled animations are useful for focusing on details within a pattern; and (5) that individual interviews are particularly useful in obtaining users' reactions to software (as opposed to having them learn the software on their own) because the interviewer can steer the interview based on the user's responses.