© 2010 Pearson Addison-Wesley. All rights reserved. Addison Wesley is an imprint of Design Human factors Implementation Evaluation HCI stages.

1-2 © 2010 Pearson Addison-Wesley. All rights reserved. Definition of HCI Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them. ACM SIGCHI Curricula for HCI (Hewett et al. 1992) http://sigchi.org/cdg/cdg2.html

1-3 © 2010 Pearson Addison-Wesley. All rights reserved. HC stages Design involves principles of design and human behavior the Implementation stage principles of computer science Evaluation stage empirical research methods common to several disciplines. There are thus four topical areas to cover in this major: Human Behavior, Design, Implementation, and Evaluation. 2-3

1-6 © 2010 Pearson Addison-Wesley. All rights reserved. Examples of HCI products include intelligent computer tutors and educational games, online communities, smartphone apps and interactive robots. Constructing an HCI product is a cyclic, iterative process that involves at least three stages. 2-6

1-7 © 2010 Pearson Addison-Wesley. All rights reserved. The Computer a computer system is made up of various elements each of these elements affects the interaction –input devices – text entry and pointing –output devices – screen (small &large), digital paper –virtual reality – special interaction and display devices –physical interaction – e.g. sound, haptic, bio-sensing –paper – as output (print) and input (scan) –memory – RAM & permanent media, capacity & access –processing – speed of processing, networks

1-8 © 2010 Pearson Addison-Wesley. All rights reserved. Interacting with computers to understand human–computer interaction … need to understand computers! what goes in and out devices, paper, sensors, etc. what can it do? memory, processing, networks

1-9 © 2010 Pearson Addison-Wesley. All rights reserved. Navigating the interface Sample of the National Cancer Institutes guidelines: –Standardize task sequences –Ensure that embedded links are descriptive –Use unique and descriptive headings –Use check boxes for binary choices –Develop pages that will print properly –Use thumbnail images to preview larger images 2-9

1-10 © 2010 Pearson Addison-Wesley. All rights reserved. How many computers in your house? –PC –TV, VCR, DVD, HiFi, cable/satellite TV –microwave, cooker, washing machine –central heating –security system can you think of more? in your pockets? –PDA –phone, camera –smart card, card with magnetic strip? –electronic car key –USB memory try your pockets and bags

1-11 © 2010 Pearson Addison-Wesley. All rights reserved. Design Concepts Eliciting from the client, formulating, and articulating functional specifications Knowing how human factors and cognitive models should inform design Knowing the principles of, and having experience with, communication design Understanding how implementation constraints should inform design Incorporating evaluation results into iterated designs 2-11

1-12 © 2010 Pearson Addison-Wesley. All rights reserved. Intuitive Design provides a professional resource to creating software with functionality that users need. However, the availability of technical functionality does not guarantee that software will be practically usable. Software that is usable for its purpose is sometimes described by programmers as “intuitive” (easy to learn, easy to remember, easy to apply to new problems) or “powerful” (efficient, effective). 2-12

1-13 © 2010 Pearson Addison-Wesley. All rights reserved. Scheiderman’s 8 golden rules of interface design 1.Strive for consistency 2.Cater to universal usability 3.Offer informative feedback 4.Design dialogs to yield closure 5.Prevent errors 6.Permit easy reversal of actions 7.Support internal locus of control 8.Reduce short term memory load 2-13

1-14 © 2010 Pearson Addison-Wesley. All rights reserved. Conceptual, semantic, syntactic, and lexical model Foley and van Dam four-level approach –Conceptual level: User's mental model of the interactive system –Semantic level: Describes the meanings conveyed by the user's command input and by the computer's output display –Syntactic level: Defines how the units (words) that convey semantics are assembled into a complete sentence that instructs the computer to perform a certain task –Lexical level: Deals with device dependencies and with the precise mechanisms by which a user specifies the syntax Approach is convenient for designers –Top-down nature is easy to explain –Matches the software architecture –Allows for useful modularity during design 2-14

1-16 © 2010 Pearson Addison-Wesley. All rights reserved. Direct manipulation 2-16 In computer science, direct manipulation is a human–computer interaction style which involves continuous representation of objects of interest and rapid, reversible, and incremental actions and feedback. [1]computer sciencehuman–computer interaction [1] As opposed to other interaction styles, for example, a command language, the intention of direct manipulation is to allow a user to manipulate objects presented to them, using actions that correspond at least loosely to manipulation of physical objects.command languageobjectsphysical objects An example of direct-manipulation is resizing a graphical shape, such as a rectangle, by dragging its corners or edges with a mouse.graphical shapemouse Others: scroll bars, zooming,thumbnails, overview maps, structure navigation etc Direct manipulation is closely associated with interfaces that use windows, icons, menus, and a pointing device (WIMP GUI) as these almost always incorporate direct manipulation to at least some degreeWIMP

1-17 © 2010 Pearson Addison-Wesley. All rights reserved. direct manipulation, and interface modes The principles of Direct Manipulation as described by Shneiderman are: An object that is of interest to the user should be continuously visible in the form of a graphical representation on the screen Operations on objects should involve physical actions (using a pointing device to manipulate the graphical representation) instead of commands with complex syntax The actions that the user makes should be rapid, should offer incremental changes over the previous situation, and should be reversible The effect of actions should immediately be visible, so that the user knows what has happened There should be a modest set of commands doing everything that a novice might need, but it should be possible to expand these, gaining access to more functions as the user develops expertise. The best-known modal interface components are probably the Caps lock and Insert keys on the standard computer keyboard, both of which put the user's typing into a different mode after being pressed, then return it to the regular mode after being re- pressed.Caps lockInsertcomputer keyboard 2-17

1-18 © 2010 Pearson Addison-Wesley. All rights reserved. Direct Manipulation :Basic principle Objects on the screen represent real-world objects Actions on computer resemble real-world actions Immediate feedback on action 2-18

1-20 © 2010 Pearson Addison-Wesley. All rights reserved. WIMP interfaces & Fitts law WIMP=Window,icon,menu,pointing devices Fitts' law – an experimental observation that the time it takes to point at a given location is related to the size of the target and also the distance from the current hand position to the target. T = K log2(A / W + 1) where A = amplitude, W = width K=index of difficulty 20

1-21 © 2010 Pearson Addison-Wesley. All rights reserved. Gesture interaction Sensing and display technologies change fast, and it’s more important to understand the principles of interaction than the details of a specific interaction device. If we consider the interaction principles that are independent of any particular hardware, these are: How does the user get content (both data and structure) into digital form? How does the user navigate around the content? How does the user manipulate the content (restructuring, revising, replacing)? 2-21

1-22 © 2010 Pearson Addison-Wesley. All rights reserved. Fitts law.. In user interfaces that require a user to make many sequences of repetitive actions (forexample, people working in telephone call centres or in data entry), it can be useful to compare alternative designs by counting the individual actions needed to carry out a particular task, including the number and extent of mouse motions, as well as all the keys pressed on the keyboard. This Keystroke Level Model can be used to provide a quantitative estimate of user performance, and to optimize the design and layout of the interaction sequence 2-22

1-23 © 2010 Pearson Addison-Wesley. All rights reserved. Human Factors –Cognitive descriptions of human performance (often called human factors by engineers) tend to be most valuable in detailed assessment and critique of a proposed design –“Human factors is that branch of science and technology that includes what is known and theorized about human behavioral and biological characteristics that can be validly applied to the specification, design, evaluation, operation, and maintenance of products and systems to enhance safe, effective, and satisfying use by individuals, groups, and organizations.” (Christensen, Topmiller, & Gill, 1988, p.7, as cited in Proctor & van Zandt, 1994, p.2)

1-24 © 2010 Pearson Addison-Wesley. All rights reserved. Human factors.. (‘ cognitive psychology’ is closely associated with ‘artificial intelligence’, investigating human performance by simulating it with machines) One of the most famous findings in cognitive psychology research, and the one most often known to user interface developers, is an observation by George Miller in 1956.Miller generalized from a number of studies finding that people can recall somewhere between 5 and 9 things at one time - usually referred to as “seven plus or minus two”.Surprisingly, this number always seems to be about the same, regardless of what the “things” are. It applies to individual digits and letters, meaning that it would be very difficult to remember 25 letters. However if the letters are arranged into five 5-letter words (apple, grape …), we have no trouble remembering them. We can even remember 5 simple sentences reasonably easily. Miller called these units of short-term memory chunks 2-24

1-25 © 2010 Pearson Addison-Wesley. All rights reserved. Cognitive Modeling Cognitive modeling is an area of computer science that deals with simulating human problem solving and mental task processes in a computerized model. Such a model can be used to simulate or predict human behavior or performance on tasks similar to the ones modeled. 2-25

1-26 © 2010 Pearson Addison-Wesley. All rights reserved. Cognitive Modeling They represent users of interactive systems They represent/model aspects of user: e.g. understanding, knowledge, intentions, processing 2-26

1-27 © 2010 Pearson Addison-Wesley. All rights reserved. Cognitive models 1. Goal and task hierarchies[+ eg GOMS (Goals, Operators, Methods and Selection)] 2.Linguistic [+ eg BNF (Backus–Naur Form)] 3.Physical and device 4. Cognitive architectural 2-27

1-30 © 2010 Pearson Addison-Wesley. All rights reserved. Other Cognitive Considerations Metaphors –Info visualization –Visual programming –Anthropomorphism Cognitive load –Fatigue, stress of task –automation vs user choice Focus of attention –multi-tasking how easy is it to return to a suspended task? User Modeling –Interfaces tailored to individuals MSR data mountain Khoros – Cantata HP CRL – Smart Kiosk

1-31 © 2010 Pearson Addison-Wesley. All rights reserved. Visual metaphor The idea of a visual metaphor is that the screen display simulates some more familiar real world object, and that the user’s mental model will then be understood by analogy to the real world. 2-31

1-32 © 2010 Pearson Addison-Wesley. All rights reserved. Human factors –Ethnographies-Anthropological field study of people in cultural, social settings –Study social relationships and their impacts on work IS 531 : Lecture 9 32

1-33 © 2010 Pearson Addison-Wesley. All rights reserved. Human factors Ethnographic methods are becoming increasingly important in HCI, to an extent that many technology companies will now employ an anthropologist as their first social science expert, rather than a psychologist Descriptions of mental models (what the user infers about the system)can be helpful in elaborating a design concept. But ethnographic observation can help to understand technology and products in completely new ways, perhaps leading to innovative new concepts. 2-33

1-34 © 2010 Pearson Addison-Wesley. All rights reserved. Automation and human control Successful integration: –Users can avoid: Routine, tedious, and error prone tasks –Users can concentrate on: Making critical decisions, coping with unexpected situations, and planning future actions 2-34

1-35 © 2010 Pearson Addison-Wesley. All rights reserved. Automation and human control Supervisory control needed to deal with real world open systems –E.g. air-traffic controllers with low frequency, but high consequences of failure –FAA: design should place the user in control and automate only to improve system performance, without reducing human involvement 2-35

1-37 © 2010 Pearson Addison-Wesley. All rights reserved. Human Factors :“Know thy user” Determine user’s skill levels is vital Age group, gender, physical and cognitive abilities & impairments, education, cultural or ethnic background, training, motivation, goals and personality Design goals based on skill level –Novice or first-time users –Knowledgeable intermittent users –Expert frequent users Multi-layer designs 2-37

1-38 © 2010 Pearson Addison-Wesley. All rights reserved. Human Factors.. World War II was a major force in bringing all of this together. New technologies, many untrained users, and profound consequences of failure highlighted the critical need for human factors research. Some of the prime industries relying on Human Factors for design consideration are: –Military technology. –Nuclear power plants. –Aviation. –Automobiles. –Consumer products. –Human-computer interaction(HCI)

1-39 © 2010 Pearson Addison-Wesley. All rights reserved. Human Information processing theory Chris Wickens has provided a famous theory about Human information processing The theory includes sensory store, perception, working memory, long-term memory,sensory memory attention, response execution, output and feedback loop. 2-39

1-40 © 2010 Pearson Addison-Wesley. All rights reserved. Perception in HCI Perception is what allows the user to see and feel when using a human computer interface. In order to understand and allow the users to see and feel, designers use colours, patterns and objects. To get user’s attention consider Intensity,Marking,Size,Choice of fonts Inverse video,Blinking,Color & Audio 2-40

1-42 © 2010 Pearson Addison-Wesley. All rights reserved. Types of memory.. Working memory Working memory is the area of conscious memory where current processing takes place - Think of it as the ‘processor’ part of a computer It can be fed by memories stored in long term memory, or by sensory input. WM has a role to play in both language understanding and calculation. In both these cases there is a need to hold information in your head while the process of interpretation of the words or calculation is being carried out. STM is an aspect of working memory (WM). Short term memory (STM) is as an area of memory that is able to hold limited information for a short time. STM was thought to be limited to the ‘magic number’ 7 plus or minus 2 pieces of information - Miller’s magic number Later research suggests that the capacity of working memory is only about 3 or 4 items - words, phrases or images 2-42

1-43 © 2010 Pearson Addison-Wesley. All rights reserved. Types of memory.. Long term memory Long term memory (LTM) is an area of memory where information is stored and can be retrieved over very long periods of time - Think of it as the ‘hard drive’ of a computer. LTM is effectively infinite. Items from LTM have to be retrieved and brought into working memory before they can be used - This is called activation. Items in working memory can be processed more easily than information that has to be retrieved from LTM, thus any system that requires recall from LTM will slow down the activity of the user. The inability to retrieve information as desired, what is termed forgetting, could be viewed as very long retrieval times. Electrical stimulation of the brain has been said to evoke long-lost memories. 2-43

1-44 © 2010 Pearson Addison-Wesley. All rights reserved. Types of memory.. Sensory memory Sensory memory is an area of conscious memory that deals with information from the senses – eyes, auditory(ears), tongue, nose(olfactory & gustatory) & haptic (touch). When we watch a film we ‘see’ thousands of still frames, which are converted by our brain into a moving image. Other examples include light traces and audio play-back. As yet, computer systems do not use taste or smell, however in the future virtual reality systems may wish to use them in order to create the atmosphere of a real experience. 2-44

1-45 © 2010 Pearson Addison-Wesley. All rights reserved. Types of Memory.. Short term memory is also very different from long term memory everything we know. Learning is the process of encoding information from short term memory into long term memory, where it appears to be stored by association with the other things we already know Current models of long-term memory are largely based on connectionist theories -we recall things as a result of activation from related nodes in a network 2-45

1-46 © 2010 Pearson Addison-Wesley. All rights reserved. Advanced UI techniques Virtual reality (VR) Augmented reality(AR) Tangible user interfaces Machine vision Paper interfaces Mixed reality Eye tracking and gaze control Surface and tabletop interaction Embodied interaction 2-46

1-47 © 2010 Pearson Addison-Wesley. All rights reserved. Virtual Reality Virtual Reality (VR), which can be referred to as immersive multimedia or computer-simulated life, replicates an environment that simulates physical presence in places in the real world or imagined worlds and lets the user interact in that world. Virtual reality artificially creates sensory experiences, which can include sight, hearing, touch, smell, and taste. computer-simulated 2-47

1-48 © 2010 Pearson Addison-Wesley. All rights reserved. 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. GPS 2-48

1-50 © 2010 Pearson Addison-Wesley. All rights reserved. Mental models Defn: The way that the user perceives that the system work Don Norman, one of the first generation of cognitive scientists investigating HCI wrote in the first popular book on the topic – The Design of Everyday Things1 - The basic claim of mental models theory is that if you know the users' beliefs about the system they are using, you can predict their behavior 2-50

1-51 © 2010 Pearson Addison-Wesley. All rights reserved. Ergonomics –Human performance and interaction with physical characteristics of tools/ machines/computers/systems –Focus on design for safety, comfort, and convenience IS 531 : Lecture 9 51

1-52 © 2010 Pearson Addison-Wesley. All rights reserved. Implementation Programming skills Familiarity with standard languages - e.g., C++, Java, HTML Rapid prototyping skill (e.g., Flash),android studio Computational literacy, i.e., knowledge sufficient for effective communication and decision making about interface construction tools and languages - e.g., Ruby on Rails, Swing, Java Multimedia authoring tools - e.g., Director, Premiere Data structures and algorithms operating systems, platforms, etc. 2-52

1-53 © 2010 Pearson Addison-Wesley. All rights reserved. Evaluation Why Evaluate? In HCI we evaluate interfaces and systems to: Determine how usable they are for different user groups Identify good and bad features to inform future design Compare design choices to assist us in making decisions– Observe the effects of specific interfaces on users 2-53

1-54 © 2010 Pearson Addison-Wesley. All rights reserved. Usability evaluation stages Formative evaluation objective is to contribute to the design of the product, by assessing specifications or prototypes before the system has been built. Its Diagnostic and error correction by nature Summative evaluation Objective is to assess usability -whether the product meets its requirement specifications, and is carried out at the end of a project with representative users after the system has been built, Larger, more established, companies spend more on summative evaluation of new products, because of the danger to their reputation if they were to release a product that was very much inferior 2-54

1-55 © 2010 Pearson Addison-Wesley. All rights reserved. Evaluation methods A. Inspection methods (no users needed!) 1.Heuristic evaluations, principles & guidelines 2.Cognitive Walkthroughs-based on scenario B. Empirical methods (users needed!) 1. Usability testing –earlier typical in the lab using metrics Observations/Ethnography 2. Controlled Experiment Comparisons,statistical analysis 3.Field studies-out in real world later in the design process 2-55

1-56 © 2010 Pearson Addison-Wesley. All rights reserved. Cognitive walkthroughs The cognitive walkthrough is a usability evaluation method in which one or more evaluators(HCI expert) work through (analog to code work through) a series of tasks and ask a set of questions from the perspective of the user. The focus of the cognitive walkthrough is on understanding the system's learn ability for new or infrequent users Focus on ease of learning. Designer presents an aspect of the design & usage scenarios. Expert is told the assumptions about user population, context of use, task details. One of more experts walk through the design prototype with the scenario. Experts are guided by standard questions. 2-56

1-57 © 2010 Pearson Addison-Wesley. All rights reserved. Usability What is Usability? ISO (ISO 9241) (Dix, 1998) define usability as effectiveness, efficiency and satisfaction with which specified users achieve specified goals in a particular environment. The standard further defines the components of the usability definition: Effectiveness: accuracy and completeness with which specified users can achieve specified goals in a particular environment Efficiency: How quick can user reach the goals? Satisfaction: the comfort and acceptability of the work system to its users and other people affected by its use. How positive is the experience 2-57

1-58 © 2010 Pearson Addison-Wesley. All rights reserved. Empirical techniques 1.Surveys-closed and open questions 2.Questionnaires- are a particular type of survey. (Interview studies of a sample population are also a form of survey). Questionnaires are generally used to gather responses from a larger sample, and can be administered by email as well as on paper 3.Field studies/tests- a follow-me-home observation approach & Think aloud 2-58

1-59 © 2010 Pearson Addison-Wesley. All rights reserved. Think aloud Users are asked to say whatever they are looking at, thinking, doing, and feeling, as they go about their task. Observers are asked to objectively take notes of everything that users say, without attempting to interpret their actions and words. Test sessions are often audio and video taped. 2-59

1-60 © 2010 Pearson Addison-Wesley. All rights reserved. REFERENCE 1. Dix Finlay Human-Computer Interaction 3 rd Edition 2.www.hcii.cmu.edu/academics/hci-undergraduatewww.hcii.cmu.edu/academics/hci-undergraduate 3) Designing the User Interface:Strategies for Effective Human-Computer Interaction Fifth Edition 4)Proctor, R. W., & van Zandt, T. (1994). Human factors in simple and complex systems. Boston: Allyn and Bacon. 6)Darnell, M. J. (2003). Bad human factors designs. Retrieved May 10, 2003 from 7)“Usability of Health Informatics Applications” retrieved from www.csun.eduwww.csun.edu 8)http://www.lauradove.info/reports/mental%20models.htmhttp://www.lauradove.info/reports/mental%20models.htm 6)http://hci.ilikecake.ie/design/memory.htmhttp://hci.ilikecake.ie/design/memory.htm 7)http://www.interface-analysis.com/IAA/usability.htmlhttp://www.interface-analysis.com/IAA/usability.html 8)http://whatis.techtarget.com/definition/cognitive-modelinghttp://whatis.techtarget.com/definition/cognitive-modeling 9)http://www.ntu.edu.sg/home/astjcham 2-60

© 2010 Pearson Addison-Wesley. All rights reserved. Addison Wesley is an imprint of Design Human factors Implementation Evaluation HCI stages.

Similar presentations

Presentation on theme: "© 2010 Pearson Addison-Wesley. All rights reserved. Addison Wesley is an imprint of Design Human factors Implementation Evaluation HCI stages."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

© 2010 Pearson Addison-Wesley. All rights reserved. Addison Wesley is an imprint of Design Human factors Implementation Evaluation HCI stages.

Similar presentations

Presentation on theme: "© 2010 Pearson Addison-Wesley. All rights reserved. Addison Wesley is an imprint of Design Human factors Implementation Evaluation HCI stages."— Presentation transcript:

Similar presentations

About project

Feedback