The effect of a hierarchical task-specific external conceptual model on the learnability and usability of microcomputer applications by novices

Abstract

This study focuses on how an external conceptual model of a microcomputer system could be constructed which would match problem-solving processes of novice users. The study's premise was that this conceptual model would aid novice users in forming initial mental models, as defined by Norman (1983), that guide them in using and understanding the system. Research findings indicate that the problem-solving process depends upon previously developed mental models of similar systems which novice users lack. Furthermore, the absence of these mental models hinders performance (the ability to use a system and accomplish a task). Researchers have agreed that a hierarchical structure is the basic form of the human problem-solving process. This study investigated the effectiveness of a hierarchically organized external conceptual model of a microcomputer system on novice users' ability to use and understand that system. Two external conceptual models were developed for the study and examined through a laboratory study which compared their effectiveness in aiding novice users to use and understand a database system. The reference manual followed traditional manual design considerations. The hierarchical model was developed using characteristics identified in novice user problem-solving. The results indicated that the hierarchical model group performed better and had a higher understanding of the system than the reference model group. The hierarchical model group was able to complete more of the assigned database tasks, with fewer errors, and spent less time with the model than the reference manual group. Although, no statistically significant result was detected in the amount of time to complete the combined tasks, the hierarchical model group was able to complete the first task faster. No evidence was indicated that the perceived difficulty of the system between the two groups was different. The findings suggest that a hierarchical external conceptual model improves the match between the human problem-solving process among novice users and the representation of microcomputer systems. They contribute to a better understanding of external conceptual model representation for novice users in assisting them to initiate the problem-solving process necessary for mental model formation of microcomputer systems.