MDI vs IDI

by: Binding Designs, LLC

First impressions last a lifetime: effect of interface type on disorientation and cognitive load

This article is about the results of a scientific research on the results of two interfaces: menu driven (MDI) and icon driven (IDI) interfaces. The paper focuses on disorientation and cognitive load as the two primary cognitive conditions in respect to the research. Users suffer from learning and memorizing information presented on a computer screen. In this paper, the interaction between IT and humans is studied. Consumer reaction and widespread adoption are two factors to measure in this study. Consistency is one theory of ease of use. This may be true. Just because a feature’s interface is consistent with other feature’s interfaces, does not make it easier to use. It may be familiar which makes it easy, but not the most optimal method of interfacing with this feature. ” Disorientation can be defined as the tendency to lose one’s sense of location in a software interface.” Disorientation is common on the web because it is so easy for so many different people to create navigation systems. There is a lack of consistency and a lot of navigations are developed poorly. A poorly developed inconsistent navigation may be the worst. The two navigation methods that will be compared can be defined as follows: “Structured menus may be clear to some but a means to disorientation for others. Icons on the other hand may be very representative to some but very confusing to others. Structured menus may be clear to some but a means to disorientation for others. Icons on the other hand may be very representative to some but very confusing to others.” Cognitive load is the amount of cognitive information to be processed by the user. Good screen design is the key to making a user be able to use the system with less frustration. Some traits of the screen are: “layout, consistency (Grudin, 1989), color, spatial display, and organizational display.” Two elements are considered: perceived usefulness (PU) and perceived ease of use (PEU). A set of tasks were asked to be completed by 59 subjects and half were assigned IDI and the other half MDI. It was set to be unbiased and the results recorded through timing and a PE/PEU based questionnaire. The tasks done in IBI took participants much longer to complete than the tasks done in MDI. This may be biased because all users were used to using software that was MDI. It may take time for the user to adjust to the new “mental model” of IBI. There is disorientation for a subject to use an unfamiliar interface. The disorientation may be the deciding factor that makes it seem like the MDI is faster to complete. If the subjects were to use both of them equally, before the experiment, then the results would not have been so biased. The PU is higher for the IBI as is concluded by the report. An emphasis on the importance of this study is granted by the new technologies such as Mobile Phones, PDAs, Navigation systems, etc… A situation that could be made up is that it is easier to use a PDA that has IDI, but during first studies, the subjects may use the MDI faster. This would probably be because they are familiar with the MDI. But, studies could show that later, the IDI has faster times. This would be because the subject is learning the IDI. If a subject had exactly the same experience with both IDIs and MDIs, then the first study might show that the IDIs are easier to use.