Lecture 2

Users’ Mental Models

Human Computer Interaction/COG3103, 2016 Fall Class hours : Monday 1-3 pm/Wendseday 2-3 pm Lecture room : Widang Hall 209 12th September

From Usability to User Experience

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Figure 1-2 User experience occurs within interaction and usage context

User’s Mental Models : The Very Ideas

• Book

– Stephen J. Payne, “User’s Mental Models : The Very Ideas” in John M.

Carroll, (2003) HCI Models, Theories, and Frameworks : Toward a

Multidisciplinary Science, CA : Morgan Kaufmann Publishers, pp. 135-156.

COG_Human Computer Interaction 3 Lecture #2

Design Philosophy

• Herb Simon:

“Engineers are not the only professional designers. Everyone

designs who devises courses of action aimed at changing existing

situations into preferred ones.

The intellectual activity that produces material artefacts is no different

fundamentally from the one that prescribes remedies for a sick patient or the one

that devises a new sales plan for a company or a social welfare policy for a state.”

– Herbert A. Simon, The Sciences of the Artificial, 1969 (p.129 of 1981 MIT press 2nd

edition)

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Intro

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Figure 1 (adapted from Norman (1988) p. 16): The problem of ensuring that the user's mental model corresponds to the designer's model arises because the designer does not talk directly with the user. The designer can only talk to the user through the "system image" - the designer's materialised mental model. The system image is, like a text, open to interpretation.

Lecture #2

Users

• Mental Models

– User’s knowledge about the system they use.

• Bounded Rationality (Simon, 1955)

– People often have to act too quickly to allow full consideration of all their relevant

knowledge – they do the best they can to achieve their goals according to the

knowledge they can bring to mind, and the inferences that knowledge supports, in the

time allowed.

– “Bounded rationality” : rationality that is bounded by the environmental constraints on

their performance, interacting with their limits on access to knowledge and the limits on

their performance, interacting with their limits on access to knowledge and the limits on

their ability to process relevant information.

COG_Human Computer Interaction 6 Lecture #2

Mental Models

• Idea 1. Mental Content vs. Cognitive Architecture : Mental Models as

Theories

– Bounded Rationality : the general limits of the human information-processing

system – the constrains on attention, retrieval, and processing.

– Human information-processing architecture : theories of the structure of the

mind.

– Contents of the mind : what do people believe about an aspect of the world,

what is the relation between these beliefs and reality, and how do the beliefs

affect their behavior?

COG_Human Computer Interaction 7 Lecture #2

Cognitive Architecture

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A model of the user based on an information processing metaphor

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Mental Models

• Idea 2. Models vs. Methods : Mental Models as Problem Spaces

– Mental models of machines can provide a problem space that allows more

elaborate encoding of remembered methods, and in which novice or expert

problem solvers can search for new methods to achieve tasks.

– Stepping through a sequence of states in some mental models of a machine, is

often called “mental simulation” in the mental-models literature, and the kind

of model that allows simulation is often called “surrogate”

– Reasoning is performed by sequential application of completely domain-

specific rules and thus is knowledge bounded rather than architecture

bounded.

COG_Human Computer Interaction 9 Lecture #2

Her - Alien Child / Hologram sequences

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https://vimeo.com/97740427

Mental Models

• Idea 3. Models vs. Descriptions : Mental Models as Homeomorphisms

– Mental models are a special kind of representation, sometimes called an

analog representation – one that shares the structure of the world it

represents.

– Example

• The spoon is to the left of the fork spoon fork

• The knife is to the left of the spoon knife spoon fork

– Such a model allows deductive inferences to be “read off”

COG_Human Computer Interaction 11 Lecture #2

Swankolab

COG_Human Computer Interaction 12 Lecture #2

Mental Models

• Idea 4. Models of Representations : Mental Models Can Be Derived

from Language, Perception, or Imagination

– Mental models can be constructed by processing language, but the same

models might also, in principle, have been constructed through

interaction with and perception of the world. Therefore a mental model

provides a way of mapping language to perception.

COG_Human Computer Interaction 13 Lecture #2

In the eyes of the animal/Marshmallow Laser Feast

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https://vimeo.com/140057053

Mental Models

• Idea 5. Mental Representations of Representational Artifacts

– The yoked state space hypothesis(Payne, Squibb, & Howes, 1990)

• To construct a conceptual model of a device, the user must conceptualize the

device's representation of the task domain. This knowledge can be

represented by three components: a device-based problem space, which

specifies the ontology of the device in terms of the objects that can be

manipulated and their interrelations, plus the operators that perform the

manipulations; a goal space, which represents the objects in terms of which

user's goals are expressed; and a semantic mapping, which determines

how goal space objects are represented in the device space.

COG_Human Computer Interaction 15 Lecture #2

Social Networking Space

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Mental Models

• Idea 6. Mental Models as Computationally Equivalent to External

Representations

– If structure-sharing is taken to be an important property of mental models,

then a mental model derived from text shares the structure of the situation,

not of the text.

– However, it is not clear that this distinction extends to mental models

derived from “reading” other representational artifacts, such as maps, or

diagrams.

COG_Human Computer Interaction 17 Lecture #2

Wishing wall by Varvara Guljajeva and Mar Canet

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http://youtu.be/MX0Z6aHZYDw

Homework

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Submission Due : 11: 59 pm Sun. 18th Sept.

Video note in a time capsule

Your Blog Post #3 - Title “Message to myself in the Future(about 10 years later?)” - Edit it in the length of 30 seconds. - Share the vimeo(or youtube) link on your blog

Contacts

• Email

– digital.sd.lab@gmail.com

• Class Blog

– http://invisiblecomputers.wordpress.com/

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