1. 1. The Psychology of Human-Computer Interaction Dr Simon Bignell Senior Lecturer in Psychology s.bignell@derby.ac.uk Week 4 Cyberpsychology (5PS505)
2. 2. Dr Simon Bignell Cyberpsychology Learning Outcomes of the Lecture To understand why psychologists should be involved in designing new technologies. To consider some elements of human-computer interaction in relation to psychology. To consider how new technologies impact on people and society.
3. 3. Contents What is HCI? Disciplines Contributing to Human-computer Interaction. Human-Computer Interaction as a Field of Study. Human Factors / Ergonomics. Systems Model vs User Model The User Interface Evolution of HCI interfaces. Human-Computer Dialog Common Ground Metaphors for Human-Computer Interaction Fittss (Fitts)Law Ubiquitous Computing. Seminar Discussion and Activity.
4. 4. Incidents: Information Overload / User Attention. Three Mile Island, 1979 What started as a minor malfunction in the system ended as the largest commercial nuclear accident in the USA. Errors in information signals indicated the reverse of the truth Poor placement of information a caution tag fitted to one system obscured the reading from another control system. Information overload too much going on. 1500 alarms in either visual or auditory modalities Poor controls a single acknowledge button silenced all alarms rather than allowed individual control. Operators were unable to break out of a cycle of assumptions that conflicted with what their instruments were telling them. Mistakes are often blamed on operators rather than on the design of the system. Poor interfaces can lead to disaster
5. 5. Dr Simon Bignell Cyberpsychology What is Human-Computer Interaction (HCI)?
6. 6. Dr Simon Bignell Cyberpsychology What is Human-Computer Interaction (HCI)? Human-computer interaction (HCI) is the study of how people interact with computing technology. HCI study is the region of intersection between psychology and the social sciences, on the one hand, and computer science and technology, on the other. Human-Computer interface. Where people meet or come together with machines or computer-based systems. Physical interface (e.g. buttons, screens, menus, etc.) Logical interface. The model a system presents a user. Set of tasks available and how theyre organized.
7. 7. What is Human-Computer Interaction (HCI)? A key design activity is to design the user-interface. For every input and output the developer must consider the interaction between the user and the computer. Because the interaction is much like a dialog between the user and the computer, user-interface design is often referred to as dialog design. The field of HCI investigates how people use computer systems, so that better systems can be designed. One aspect is concerned with technological innovation (e.g. better input devices, like electronic pen etc.) The other aspect is concerned with the human element (e.g. how people reason, solve problems and interact with computers).
8. 8. Disciplines Contributing to Human-Computer Interaction Computer Science Cognitive Psychology /Science Artificial Intelligence HCI Social & Organisational Psychology Sociology Ergonomics
9. 9. Human-Computer Interaction as a Field of Study User-interface design techniques and HCI as a field of study evolved from studies of human interaction with machines in general human factors engineering or ergonomics Formal study of human factors began in World War II, when aerospace engineers studied the effects of arranging controls in cockpit. What the pilot does is the human factor that engineers realised was beyond their control.
10. 10. Dr Simon Bignell Cyberpsychology How does HCI / Human Factors differ from Experimental Psychology? Experimental Psychology is the scientific study of mind, brain, and behavior Why do humans think and behave the way they do? HCI / Human factors is the study of human behavior in the context of technological systems. How should we design a system to accommodate the way humans think and behave? The study of how humans accomplish work-related tasks in the context of human-machine system operation, and how behavioral and non-behavioral variables affect that accomplishment Meister (1989)
11. 11. Dr Simon Bignell Cyberpsychology Human Factors Human Factors psychology examines the capabilities of humans and how these constraints and abilities affect design. Therefore, it is concerned with cognitive issues and research concerning humans interpretation of stimuli and our abilities to deal with certain situations. The goal is to design systems with these capabilities and limitations in mind. Cognitive issues that must be considered: Memory (span, retrieval, storage capacity). Visual and auditory capabilities/interpretations. Attention capacity (selective, focused, divided). Judgment of tones, size, loudness, brightness. Interpretation of coding (traffic lights).
12. 12. Dr Simon Bignell Cyberpsychology Emergence of the field of Human-Computer Interaction The field of human factors was associated with engineering, since engineers designed machines. But engineers often found human factors frustrating (different personality types). Gradually specialists emerged who drew on many disciplines to understand people and their behaviour. Disciplines drawn on for HCI: Cognitive psychology. Computer science. Social psychology. Linguistics. Sociology. Anthropology.
13. 13. Dr Simon Bignell Cyberpsychology The User Model (of the system) Is what the user thinks happens (within the system). Much of the users model is a logical model of the system. A logical model can be detailed, so a user must know quite a few details to operate the system. People want to learn by doing, but this inclines them to opportunistically jump around in sometimes brittle learning sequences. They want to reason things out and construct their own understandings, but they often draw incorrect inferences They try to engage and extend prior knowledge and skill, which can lead to interference or overgeneralisation.
14. 14. Dr Simon Bignell Cyberpsychology The System Model Is what really happens (within a complex computer systems). Designers model (of the system). How the designer sees and understands the system. Problems with user interfaces can be considered as resulting from mismatches between the users model of the system and the designers model. Leads to attempt to study how users view systems and how designers view systems can be a big gap!
15. 15. Dr Simon Bignell Cyberpsychology The User Interface: GUI / Menus Users are given predetermined choices, they are often part of a WIMP interface (point & click). Windows and window managers Icons Menus Pointing devices. Enforce a hierarchy on the users goals. Represent well-trodden paths - you can do only what the designer envisioned.
16. 16. Dr Simon Bignell Cyberpsychology Many people think of the user interface as a component added to the system near the end of the development process. This view is changing as user interfaces become more important and systems become more interactive. To the end user, the user interface is the system The user interface is everything the end user comes into contact with while using the system physically, perceptually and conceptually. Therefore, consideration of the user interface should come early in the development process. The User Interface: GUI / Menus
17. 17. Dr Simon Bignell Cyberpsychology The User Interface: Direct Manipulation Interfaces Post-WIMP interfaces are found on devices that do not have room for a mouse. Mobile devices, phones, iPods, iPads, PDAs etc. Representations behave as if they were the objects they represent. Involves dragging, selecting, opening, closing and zooming actions on virtual objects. This reduces the distance between users and their goals. Consistent with what you see is what you get (WYSIWYG). Exploits users knowledge of how objects behave in the physical world (various metaphors). Continuous representation of the objects of interest. Physical actions, not complex syntax. Easy to learn, easy to remember.
18. 18. Dr Simon Bignell Cyberpsychology Novices can learn the basic functionality quickly. Experienced users can work extremely rapidly to carry out a wide range of tasks, even defining new functions. Intermittent users can retain operational concepts over time. Error messages are rarely encountered. Users can immediately see if their actions are furthering their goals and if not, do something else. Users experience less anxiety. Users gain confidence and mastery and feel in control. Why are Direct Manipulation interfaces enjoyable?
19. 19. Dr Simon Bignell Cyberpsychology People are different from computers, and human-human interaction is not necessarily an appropriate model for human operation of computers. Since computers can display information 1000 times faster than people can enter commands, it seems advantageous to use the computer to display large amounts of information and allow novice and intermittent users simply to choose among the items. (Schneiderman, 1986) Why are Direct Manipulation Interfaces Enjoyable?
20. 20. Dr Simon Bignell Cyberpsychology Some problems with Direct Manipulation interfaces Sometimes: information overload or screen clutter. Not all tasks can be represented by objects. its hard to represent abstract things. DM must function in the here and now. icons can be just as cryptic as words. With DM, user is responsible for doing everything; but some tasks are better achieved by delegating. e.g. spell checking. repetitive actions are tedious! Moving a mouse around the screen can be slower than pressing function keys to do same actions.
21. 21. Dr Simon Bignell Cyberpsychology Evolution of HCI interfaces 1950s - Interface at the hardware level for engineers - switch panels. 1960-70s - Interface at the programming level - COBOL, FORTRAN. 1970-90s - Interface at the terminal level - command languages. 1980s - Interface at the interaction dialogue level - GUIs, multimedia. 1990s - Interface at the work setting - networked systems, groupware. 2000s - Interface becomes pervasive. RF tags, Bluetooth technology, mobile devices, consumer electronics, interactive screens, embedded technology, information appliances.
22. 22. Dr Simon Bignell Cyberpsychology Human-Computer Dialogue Person - Person Computer - Computer
23. 23. Human-Computer Dialogue Some kinds of human conversations are scripted - who takes the initiative is relatively fixed. In other kinds of conversation, neither person takes all the initiative. What can go wrong? A dialog can be under-determined. E.g. when the user is mystified about what to do next and is forced to take the initiative (a blank screen, cryptic commands). A dialog can be over-determined. E.g. When a system is authoritarian and takes too much initiative (unnatural constraints).
24. 24. Dr Simon Bignell Cyberpsychology Human-Computer Dialogue Ideally, initiative should be flexible. Interfaces that take the initiative are better for novices. Interfaces that let the user take the initiative are better for experts. An interface is over- or under- determined with respect to a particular user.
25. 25. Dr Simon Bignell Cyberpsychology Human-Computer Dialogue Exploring and browsing: Similar to how people browse information with existing media (e.g. newspapers, magazines, libraries, pamphlets) Information is structured to allow flexibility in way user is able to search for information. Browsers, hypertext, links Virtual reality will present new ways of interacting.
26. 26. Dr Simon Bignell Cyberpsychology Human-Computer Dialogue
27. 27. Dr Simon Bignell Cyberpsychology Different styles of interacting Commands typing commands via keyboard; function key shortcuts Menus selecting from pre-determined choices Direct manipulation acting on objects and interacting with virtual objects Conversational dialogue systems interacting with the system as if having a conversation Exploring, browsing, & foraging for information finding out and learning things browsers (different from menus)
28. 28. Dr Simon Bignell Cyberpsychology Eliza, Computer Therapist ELIZA is a computer program and an early example of primitive natural language processing (NLP). http://psych.fullerton.edu/mbirnbaum/psych101/Eliza.htm http://www.manifestation.com/neurotoys/eliza.php3 ELIZA was written at MIT by Joseph Weizenbaum between 1964 and 1966. Also: A.L.I.C.E. (Artificial Linguistic Internet Computer Entity) http://alice.pandorabots.com When the original ELIZA first appeared in the 60's, some people actually mistook her for human. The illusion of intelligence works best, however, if you limit your conversation to talking about yourself and your life.
29. 29. Dr Simon Bignell Cyberpsychology Turing Test The Turing test is a test of a machine's ability to exhibit intelligent verbal behaviour similar to that of a human. The standard interpretation of the Turing test, in which player C, the interrogator, is tasked with trying to determine which player A or B is a computer and which is a human. The test was introduced by Alan Turing in his 1950 paper Computing Machinery and Intelligence, which opens with the words: I propose to consider the question, 'Can machines think? Later rephrased as: Are there imaginable digital computers which would do well in the imitation game?
30. 30. Dr Simon Bignell Cyberpsychology Common Ground in HCI Successful grounding in communication requires parties to coordinate both the content and process. Computer-mediated communication presents potential barriers to establishing mutual understanding. Grounding occurs by acknowledgement of understanding through verbal, nonverbal, formal, and informal acknowledgments. But commuter-mediated communications reduce the number of channels through which parties can establish grounding. Common Ground or Grounding in communication was proposed by Herbert Clark & Susan Brennan. It comprises the collection of mutual knowledge, mutual beliefs, and mutual assumptions, that is essential for communication between two people.
31. 31. Dr Simon Bignell Cyberpsychology The design of human-computer interaction is a problem that primarily involves the designers meaning and the users understanding. When software use is successful The designer and the user carry out a kind of collaboration but both have to work at it. The designers meaning (ideally) becomes the users understanding. A variety of linguistic and nonlinguistic signals are used. E.g., labels, icons, actions, sounds, messages, etc. Signal use is really language use. Meaning and understanding depend on the notion of common ground. Common Ground in HCI
32. 32. Dr Simon Bignell Cyberpsychology Common Ground in HCI When the normal function of common ground in a language use setting is impaired, people are forced to work harder cognitively to accomplish their goals What we call human-computer interaction takes place in the secondary layer of software use In this layer, the user participates in a direct interaction with the computer (as opposed to the designer). The interaction is designed to resemble a joint activity in a face-to- face setting But this setting is not equivalent with a face-to-face setting between people The user and the computer use different communication languages and their tools for conveying and receiving are mismatched.
33. 33. Dr Simon Bignell Cyberpsychology Metaphors for Human-Computer Interaction The term metaphor describes the overall concept you may use to organize all the objects and actions in an interface into a coherent whole. Having a metaphor can tell you how you might use something. Three major metaphors in HCI Direct manipulation metaphor The user interacts directly with objects on the display screen. Objects are made visible so the user can point at them and manipulate them with the mouse or arrow keys Desktop metaphor. The display screen includes an arrangement of common desktop objects. Document metaphor. Data is conceptualized as physical paperwork.
34. 34. Dr Simon Bignell Cyberpsychology Useful Metaphors Text editing as using a typewriter. Voice mail as answering machine or mailbox. Data as files (in folders or directories), represented as icons on desktop in windows. Deleting a file as throwing it in the trash. Applications as tools (with icons). Programming as building objects. Programming as directing actors on a stage. Applications as agents.
35. 35. Dr Simon Bignell Cyberpsychology Example: Fittss (Fitts) Law
36. 36. Dr Simon Bignell Cyberpsychology Example: Fittss (Fitts) Law Predicts that: The time required to rapidly move to a target area is a function of the distance to the target and the size of the target. proposed by Paul Fitts in 1954. Fitts's law is used to model the act of pointing, either by physically touching an object with a hand or finger, or virtually, by pointing to an object on a computer monitor using a pointing device. Buttons and other GUI controls should be a reasonable size; it is relatively difficult to click on small ones. Edges and corners of the computer monitor are particularly easy to acquire with a mouse, touchpad or trackball.
37. 37. Dr Simon Bignell Cyberpsychology Augmented Reality Augmented reality (AR) is a live direct or indirect view of a physical, real-world environment whose elements are augmented (or supplemented) by computer- generated sensory input such as sound, video, graphics or GPS data. Techniques include speech recognition systems that translate a user's spoken words into computer instructions and gesture recognition systems that can interpret a user's body movements by visual detection or from sensors embedded in a peripheral device such as a wand, stylus, pointer, glove or other body wear.
38. 38. Ubiquitous Computing: In contrast to desktop computing, ubiquitous computing can occur using any device, in any location, and in any format.
39. 39. Dr Simon Bignell Cyberpsychology Recommended Reading Don Norman: The Design of Future Things http://youtu.be/wQmw EjL6K1U?list=PL818A 65742B734849
40. 40. Any questions?
41. 41. Seminar Activity 1: Discuss 1. You have been commissioned to evaluate a new generation mobile phone. Describe how you would fulfil this commission, justifying your choice of methodology. 2. Is it better to interact with computational devices through direct manipulation or by conversing with agents? Why? 3. A science fiction writer describes humans in the future as socially isolated without skills at human interaction. Discuss why this view fails to take into account the wide range of ways that computers facilitate communication.
42. 42. Seminar Activity 2: Human Considerations in Software Design Consider 5 different users: 1. A University of Derby student trying to do research for an essay on the Web. 2. An adult on using tax preparation software at home. 3. A young woman with Cerebral Palsy who is typing coursework for a module. 4. A child playing a computer-video game. 5. An octogenarian grandparent sending email to faraway grandchildren. Questions Q: What do we need to know about each of them in order to make the software that they are using accessible? Q: What kinds of things do we need to consider in our designs? Q: What do we know about Psychology that will guide our designs?