Mental Models in HCI Design

1. G063 - Mental Models The Psychology of HCI design

2. How would you describe…..?: • how to use a light switch • how to engage 1st gear in a Ferrari sports car • how to select ITV on a TV • how to pause a DVD or music track or recorded programme • how to launch Word on a Windows computer

3. Learning Objectives: By the end of this topic you should be able to: • define the term ‘Mental Model’ • describe how ‘Mental Models’ can be applied to the design of a user interface; • discuss the importance of designing a system model which matches the user's mental model;

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9. Mental Models : • we view the world as a series of causes and effects • “if I do this.…. then that will happen” • we have preconceived ideas in our mind • of how things should work • preconceived ideas = ‘Mental Model’ • we predict the results of an action based on prior experience: • “I’ve seen this before, so I think that will also happen this time” • mental models form the basis of any interaction with an HCI

10. Mental Models and designing an HCI: A system designer needs to consider that: • users will bring their own mental models to a system This means that: • users tend to learn to use a new system by trial and error • using what they already know • users will try to predict the behaviour of a new system • based on their past experiences

11. Importance of matching the HCI to the user's mental model. So .... HCI designers must consider user’s mental models, because ...... • if HCI matches mental model then = intuitive use • if HCI looks and behaves in a familiar way • a user will find a new system easy to learn and remember • know what is likely to happen next as a result of an action • be confident using the system • if HCI is inconsistentwith the mental model, user may get lost using the interface

12. Importance of matching the HCI to the user's mental model. • less training time required • because HCI will be what user expects • increased productivity • as less training is required • less resistance to using the new HCI • as it works the way they think it should