Summary INF3720_ Human-Computer Interaction Study Notes.

INF3720_ Human-Computer Interaction Study Notes. What is Interaction Design? Main Goals of this Chapter:  Explain the difference between good and poor interaction design  Describe what interaction design is and how it relates to HCI and other fields  Explain what usability is  Describe what is involved in the process of interaction design  Outline the different forms of guidance used in interaction design  Enable you to evaluate an interactive product and explain what is good and bad about it in terms of the goals and principles of interaction design Good and Poor Design  Central concern of interaction design: products that are USABLE o Easy to use o Effective 2 o Enjoyable  Example: Marble interface versus Voicemail: an incoming message signaled by a marble dropping through- you grab it and drop it to play the message (good interface but breaks down if system gets more complex) What to Design Who will use it? Where are they going to be used? What kinds of activities will it support? A key question: How do you optimize the users' interactions with a system, environment or product, so that they match the users activities that are being supported and extended Match goals to users - get them involved  Take into account what people are good and bad at  Consider what might help people with the way they currently do things  Thinking through what might provide quality user experiences  Listening to what people might want and getting them involved in design  Using tried and tested user-based techniques during the design process Interaction Design: Definition: "Designing interactive products to support people in their everyday and working lives" Interaction Design comes from a multidisciplinary background, extends and enhances the way people work, communicate and interact Interaction Design involves four basic activities: 1. Identifying needs and establishing requirements 2. Developing alternative designs that meet those requirements 3. Building interactive versions of the designs so that they can be communicated and assessed 4. Evaluating what is being built throughout the process Evaluating what has been built is the heart of Interaction Design 3 Three characteristics of the Interaction Design Process: 1. Users involved throughout the development of the project 2. Specific usability and user experience goals should be identified, documented and agreed upon at the beginning 3. Iteration through the four activities (above) is inevitable The Goals of Interaction Design: Usability Goals & User Experience Goals - Usability Goals: concerned with meeting a usability criteria (e.g. efficiency) Effectiveness - how good system is at doing what it is supposed to Efficiency - the way a system supports users in carrying out their tasks Safety - protecting the users from dangerous conditions / undesirable situations Utility - extent to which the system provides the right kind of functionality so that users can do what they need or want to do Learnability - how easy a system is to learn to use Memorability - how easy a system is to remember how to use, once learned - User Experience Goals: User experience is what the interaction with the system feels like to the users (subjectively) Satisfying; enjoyable; fun; entertaining; helpful; motivating; aesthetically pleasing; support creativity; rewarding; emotionally fulfilling Usability: Design and Usability Goals (generalized abstractions) Norman's Design Principles: Visibility - functions can be seen Feedback - necessary part of interaction Constraints - ways of restricting what kinds of interaction can take place Mapping - relationship between controls and what happens Consistency - similar operations / use similar elements for achieving similar goals Affordance - attribute of an object that allows people to know how to use it 4 Usability Principles / Heuristics (heuristics are design principles used in practice - more prescriptive usability principles that are used as a basis for evaluating a system / prototype) Nielsen's 10 Usability Principles: Visibility of System Status Match between system and real world User control and freedom Consistency and standards Help users recognize, diagnose and recover from errors Error prevention Recognition rather than recall Flexibility and efficiency of use Aesthetic and minimalist design Help and documentation There are always tradeoffs with usability - can't over constrain things, because it limits how much info is displayed (top) Chapter 2: Understanding and Conceptualizing Interaction have a clear understanding of what, why and how you are going to design something before writing any code. Goals of the chapter: Explain what is meant by the problem space Explain how to conceptualize interaction Describe what a conceptual model is and explain the different kinds Discuss the pros and cons of using interface metaphors as conceptual models Debate the pros and cons of using realism versus abstraction at the interface Outline the relationship between conceptual design and physical design 5 Understanding the Problem Space - the problem with solving a problem on the nuts and bolts level is that critical usability goals and user needs can be overlooked - the design of physical aspects are best done AFTER we understand the nature of the problem space - to understand the problem space: clarify usability and user experience goals. Make explicit your implicit assumptions and claims. Framework for making your implicit assumptions explicit: reason through your assumption about why something might be a good idea this enables you to see the strengths and weaknesses of the proposed design Conceptual Models A conceptual model is a description of the proposed system in terms of a set of integrated ideas and concepts about what it should do, behave and look like, that will be understandable by the users in the manner intended. "The most important thing to design is the users conceptual model." (David Liddle, '96) To Develop a Conceptual Model: Envision the proposed product based on users' needs and requirements Do iterative testing What kind of interaction mode would support this? Which interaction mode to use, and which interaction style to use? Concrete solutions to support the above comes last Development should be done using: iteration, using a number of methods, by sketching out ideas, storyboarding, and scenarios, and by making use of prototypes Two types of conceptual models are: Those based on activities 1. Instructing: describes how users carry out their tasks through instructing the system what to do (1-way process: like word processing, CAD, email) 2. Conversing: based on the idea of a person conversing with the system where the system acts as a dialogue performer (2-way process: such as search engines, advisory systems, etc) 6 3. Manipulating and Navigating: manipulating and navigating through a virtual world by using users' knowledge of the real world (like video games, virtual reality) 4. Exploring and Browsing: allows people to browse / navigate through information Those based on objects based on objects or artifacts, and are more specific than those based on activities (focus on a particular object in a particular context - for example: a spreadsheet, based off of a ledger sheet) The best type of conceptual model to use depends on the nature of the activity. Often the best answer is a hybrid (such as shopping on the Internet). However, mixing conceptual models will raise the complexity of the system. Interface Metaphors definition: a conceptual model that has been developed to be similar in some ways to aspects of a physical entity, but that also has its own behaviors and properties Interface metaphors combine the familiar with new concepts Benefits: a good orientation device Drawbacks: often the metaphor looks / feels like the physical entity, when they should just map the familiar with the unfamiliar so that users can learn the new (unfamiliar) There is a growing opposition to metaphors because they can break the rules of the object they represent, they can be too constraining, can conflict with design principles, can cause misunderstanding of system functionality, can limit the designer's imagination, and can have overly literal translation of existing bad design. See Metaphors description for more information. Interaction Paradigms - moving away from WIMP interface / paradigm - new paradigms: ubiquitous computing, pervasive computing, wearable computing, augmented reality, attentive environments From Conceptual Models to Physical Design Interaction design is an ITERATIVE PROCESS, involving: cycling through various design processes and different levels of detail thinking through a design problem understanding users needs coming up with possible models prototyping models 7 evaluating them thinking about design implications making changes etc... The book describes ways of DOING INTERACTION DESIGN First pass: thinking about the problem space Second pass: more extensive information gathering about users’ needs and problems Third pass: continue explicating the requirements through models Fourth pass: Fleshing out models using variety of user-centered methods. Such as: prototyping, storyboarding, physical objects, informally asking users what they think. Issues in testing prototypes: Way information is to be presented and interacted with What combinations of media Kinds of feedback What combinations of input and output devices to use Whether to provide agents and in what format Whether to design operations to be hardwired or through physical objects or software What kinds of help to provide and in what format Physical design decisions come out of conceptual decisions (i.e. what information, how to structure graphical objects, what feedback navigation and mechanisms, what kinds of icons…). These kinds of design decisions need user testing to ensure usability goals. (top) Chapter 3: Understanding Users This chapter focuses on USERS and COGNITION. Cognitive aspects of Interaction Design include: what humans are good and bad at 8 how this knowledge can be used to inform design of technologies that, extend human capabilities and compensate for their weaknesses Main aims of chapter: What cognition is and why it is important for I-D Main ways cognition has been applied to I-D Number of examples from cognitive rese4arch Explain what mental models are Give examples of conceptual frameworks useful for I-D Enable you to try to elicit a mental model and understand what it means Norman said there are two modes of cognition: Experiential (real world experiences) and Reflective (thinking, comparing, deciding, etc). Both are necessary for everyday life. Cognition has been described in SIX KINDS OF PROCESSES: 1. Attention - selecting things to concentrate on 2. Perception / Recognition - how information is acquired from the environment via sense organs and translated into experiences (vision is the most dominant) 3. Memory - recalling various knowledge. We filter what knowledge to process / memorize. (most researched area) 4. Learning - how to do something (like learning to use a program) 5. Reading / Speaking / Writing - using language 6. Problem Solving / Planning / Reasoning / Decision Making - involves reflective cognition Often designers try to emulate the physical world with designs in the digital world. Sometimes this works well, other times it doesn't. Conceptual Frameworks for Cognition: Mental Models Information Processing External Cognition 9 Users' Mental Models - defined as: when people are using a system, they develop knowledge of how to use the system and to lesser extent how the system works. - the mental model is used to help people carry out tasks. It can also give suggestions on what to do in unpredictable situations - in cognitive psychology, mental models are defined as some sort of internal construction of the external world that are manipulated enabling predictions and inferences to be made - w/r/t system design: ideally, the users' mental models should match the designer's conceptual model - to increase transparency- might make system image easier to learn (p. 95 example?) Information Processing - another approach to conceptualize how the mind works: through metaphors and analogies - thinks of the mind as an information processor - mental representations can be images, mental models, rules, other knowledge forms the human processor model (Card, et. al 1983) is the best known approach (see p. 96) model predicts which cognitive processes are involved when a user interacts with a computer, allowing for calculations to be made on how long it will take a user to complete a task this is helpful for comparing different interfaces (efficiency) the approach is based on modeling mental activities that happen exclusively in the head. There are always external cues in the environment... so how truly representative are these models? - there has been an increase in people studying cognitive activities 'in the wild' - in the context in which they take place (how can things in the environment aid human cognition and lighten the cognitive load?) Alternative frameworks have been suggested: External cognition and Distributed Cognition External Cognition main idea: people interact with or create information through using a variety of external representations (books, etc.) - an impressive array of technology has been created by humans to aid cognition (calculators, pens, etc) 10 - these tools have combined with external representations to extend and support our ability to carry out cognitive activities. - some of the main goals of this: Externalizing to reduce memory load (external representations / cues as reminders) Computational offloading (using a tool / device to carry out a computation - like a pen / paper to do a math problem) Note: representation of the task is key- imagine the difficulty of multiplication if the numbers were represented as Roman numerals Annotating / Cognitive tracing (modifying representations to show changes - like crossing something off a list Back to Interaction Design: PROVIDE EXTERNAL REPRESENTATIONS AT THE INTERFACE TO REDUCE MEMORY LOAD (visualizations, cues, etc). Informing Design: From Theory to Practice Theories, models and frameworks provide abstractions for thinking about phenomena. They provide generalizations, but can be difficult to digest. For this reason researchers have tried to make them more practical by providing design principles / concepts, design rules, analytic methods and design / evaluation methods. This has helped - for instance - the human processor model (Card, 83) which has been simplified into GOMS. (top) Chapter 4: Designing for Collaboration and Communication humans are SOCIAL beings Purpose of the chapter: look at ways interactive systems could be developed to support and extend communication and collaboration between peoples. Social Mechanism in Communication and Collaboration: Rules, procedures and etiquette have been established to help people know how to behave in social groups, such as: Conversational mechanisms- to help the flow of talk and to help overcome breakdowns Coordination mechanisms- to allow people to work / interact together Awareness mechanisms- to find out what is happening, what others are doing and to let others know what is happening 11 Conversational Mechanisms: "turn-taking" helps coordinate conversation Implicit cues and Explicit cues (indirect vs. direct / obvious) Turn taking rules: speaker chooses next speaker by asking question / request, etc. Back channeling, body orientation, gaze, gestures are used to signal to others the flow of conversation Farewell rituals help end a conversation (bye, see ya later) Breakdowns in conversation occur when someone is ambiguous and it gets misinterpreted (followed by a re-questioning) Conversations can take the form of arguments, discussions, debate, chat, etc. How to design collaborative technologies to support conversation: First, how do technology-mediated conversations compare to FTF? Do the same rules apply? Are there more breakdowns? How do they get repaired? Design implications: A key issue has been to determine how to allow for and support people to carry on communicating as if they were in the same place, even thought they are geographically separated. Some existing apps: phone, videophone, email, IM, videoconferencing, chatrooms, SMS texting How successful are these? Do they mimic or extend existing ways of conversing?