Thesis - Teknisk Design

Components of usabilityHere it will be presented the five-component model. If we take into consideration thelevels of improvement we will have guessability, lernability, experienced userperformance (EUP) and system potential. Out from that scale there is a special butnot less important component re-usability.GUESSABILITY“Guessability is the effectiveness, efficiency and satisfaction with which specifiedusers can complete detailed tasks with a particular product for the first time”.(Jordan, P. W. 1998).ProductsProducts that need good guessability are those whose users are one-off, meaningthat it will be used just for one time when necessary. An example of this type ofproducts are emergency tools, when an accident is occurring you will have to use itfor the first time and you have to guess easily how to use it because it is a matter oftime to get it worse. Taking commercial implications into consideration, the lack ofguessability may put off products that might have been comparatively easy to use inthe long-term. Because when buying the user consider is really difficult to figure outhow to use the product. (Jordan, P. W. 1998).LEARNABILITY“Learnability is the effectiveness, efficiency and satisfaction with which specifiedusers can achieve a competent level of performance on specified task with aproduct, having already completed those tasks once previously.” (Jordan, P. W.1998).ProductsThe range of products that need a short time of learnability is wide, it includes theself-taught products and products with short training time. A useful example of thatare tools which functioning is learned in a course, and you have a set time to learnhow to use it (Jordan, P. W. 1998).EXPERIENCE USER PERFORMANCE (EUP)“The effectiveness, efficiency and satisfaction with which specified experiencedusers can achieve specified tasks with a particular product.”It is the time in which your performance has not significant changes after havebeen using the product several times to perform a particular task (Jordan, P. W.1998).ProductsProducts with little pressure to learn quickly but with a need of high performanceonce the product operation has been learned are suitable as EUP. For example usersof software packages use a lot of time to become good in a program but oncelearned they are quite quick managing it (Jordan, P. W. 1998).48