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 ====== CS 352 ====== ====== CS 352 ======
 +
 +===== Project =====
 +  * [[project/start]]
  
 ===== HCI ===== ===== HCI =====
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     * Opens up door of interpretation/rationalization.     * Opens up door of interpretation/rationalization.
  
 +==== Related: Diary Study ====
 +
 +  * Subject asked to keep journal of daily activities.
 +    * Record actions, reasons, and other observations.
 +  * Not always subjective.
 +  * Prevents researcher from having to be everywhere 24/7.
 +
 +==== Interviews ====
 +
 +  * 3 types:
 +    * Structured:
 +      * Well-defined agenda.
 +      * Efficient.
 +      * Require training.
 +    * Unstructured:
 +      * No agenda.
 +      * Let subject go in whatever direction they need to go.
 +      * Difficult to not influence direction.
 +      * Inefficient.
 +      * Less training.
 +    * Semi-structured:
 +      * Good balance of training/efficiency.
 +      * Often appropriate.
 +
 +=== Semi-Structured Interviews ===
 +
 +  * Predetermine data of interest - know why you are asking questions, don't waste time.
 +  * Guidelines:
 +    * Stay concrete (specific).
 +      * "So when the new guy joined the team and hadn't gotten his email account set up yet, what happened then?" vs. "What generally happens here when someone new joins the team?"
 +    * Signs to look for:
 +      * Interviewee waves hand and looks up at ceiling => generalization coming.
 +      * Use of passive voice, "generally", "usually", "should", "might"
 +
 +==== Surveys ====
 +
 +  * General Criteria
 +    * Make questions clear and specific.
 +    * Ask some closed questions with a range of answers.
 +      * Sometimes also have a no opinion option, or other answer option.
 +    * Do test run with two or three people.
 +  * Likert Scale
 +    * Usually odd # of points: 5, 7 point scale; agree to disagree.
 +    * Could also use words for each level.
 +    * Sometimes need to use black & white answer questions to get a normalization range.
 +  * Other Typical Questions
 +    * Rank importance of each of these items...
 +    * List the four most important tasks that you perform (open question).
 +    * List the pieces of information you need to have before making a decision about X, in order of importance.
 +    * Are there any other points you would like to make?
 +
 +===== Participatory Design =====
 +
 +  * Scandanavian history.
 +    * Scandanavia has fairly strong labor unions.
 +    * Workers involved in all decisions.
 +  * Emphasis on social and organizational aspects.
 +  * Based on study, model-building, and analysis of new and potential future systems.
 +  * User is a part of the team.
 +    * Immediate feedback.
 +    * Sanity checking.
 +    * Much tighter feedback cycle.
 +
 +===== User Centered Design =====
 +
 +==== Input & Output ====
 +
 +  * Gather data:
 +    * Surveys/questionnaires.
 +    * Interviews.
 +    * Etc.
 +
 +=== Represent Data ===
 +
 +== Task Outline ==
 +
 +  * List what task is about.
 +  * Add progressive layers of detail as you go.
 +  * Know in advance how much detail is enough.
 +  * Can add linked outlines for specific subtasks.
 +  * Good for sequential tasks.
 +  * Does not support parallel tasks well.
 +  * Does not support branching well.
 +
 +== Use Cases/Scenarios ==
 +
 +  * Describe tasks in sentences.
 +  * More effective for communicating general idea of task.
 +  * Scenarios: "informal narrative description"
 +    * Focus on tasks/activities, not system (technology) use.
 +  * Use Cases
 +    * Focus on user-system interaction, not tasks.
 +    * How to do a task using the system, not what tasks to do.
 +
 +== Hierarchical Task Analysis ==
 +
 +  * Graphical notation & decomposition of tasks.
 +  * Goals -- what the user wants to achieve.
 +  * Tasks -- do these to achieve the goals.
 +  * Looping, conditionals integrated.
 +  * See slides for example hierarchy.
 +  * Types of Plans:
 +    * Fixed sequence
 +    * Optional tasks
 +    * Waiting events
 +    * Cycles
 +    * Time-sharing
 +    * Discretionary
 +
 +== ER Diagram ==
 +
 +  * Objects/people with links to related objects.
 +    * Stress relationship between objects and actions.
 +  * Close to the type of thing you would say to a DB designer or programmer.
 +  * More difficult for user to understand.
 +  * No way to represent knowledge, ideas, motivation, etc.
 +  * Lends itself better in specifying to a developer what he needs to create.
 +
 +== Flow Charts ==
 +
 +  * Many types.
 +    * Decisions
 +    * Actions
 +    * Information flow
 +  * Combines ERD with sequential flow, branching, parallel tasks.
 +  * Tracks something being moved around.
 +  * Visually appealing, easy to understand.
 +  * More abstract than HTA.
 +  * Much quicker overview of system.
 +
 +===== Midterm =====
 +
 +  * What is usability engineering/HCI/user-centered design?
 +    * Define
 +    * Describe process/target problems
 +    * Arguments for UE/HCI/UCD/UE/HCI/UCD in historical context
 +  * Basics of human subjects research
 +    * Some history/background
 +    * Importance of Milgram experiments
 +    * Basics of Belmont report
 +  * Studying Users
 +    * Describe methods discussed in class
 +    * Argue pros & cons of each, different variations
 +    * Propose an approach to studying a given hypothetical place/situation, and argue why
 +    * How to organize and analyze data
 +
 +===== Prototyping & Design =====
 +
 +==== What is a prototype? ====
 +
 +A prototype is a simplification of a system.
 +
 +In interaction design, it could be:
 +  * Screet sketches
 +  * Storyboard
 +  * Slide show
 +  * Video simulation
 +  * Lump of wood (Physical mock up)
 +  * Software with limited functionality
 +
 +==== Why prototype? ====
 +
 +Put many ideas out there. By making prototypes, you can evaluate many options effectively.
 +
 +Facilitates evaluation:
 +
 +  * Stakeholders can see, hold, interact with.
 +  * Team members can communicate more effectively.
 +  * Test ideas yourself.
 +  * Encourages reflection.
 +  * Answer questions, support designers in choosing among alternatives.
 +
 +==== What to prototype? ====
 +
 +  * Work flow, task design
 +  * Screen layouts and information display
 +  * Difficult, controversial, critical areas
 +
 +==== Compromises ====
 +
 +All prototypes involve compromises. For software prototyping there may be a slow response, stetchy icons, limited functionality, etc.
 +
 +==== Low Fidelity Prototyping ====
 +
 +  * Rough prototype of system.
 +  * Uses medium unlike the final medium.
 +  * Quick, cheap, easily changed.
 +  * Encourages high level criticism; problems with conceptual models and fundamental usability or functionality issues.
 +  * Users unafraid to suggest major changes.
 +
 +=== Storyboards ===
 +
 +  * Often used with scenarios.
 +  * Indicate a series of events.
 +
 +==== High Fidelity Prototyping ====
 +
 +  * Looks and behaves like a subset of the final system.
 +  * Commanly used tools: Director, VisualBasic, Smalltalk
 +  * Users may think they have a full system (problem)
 +  * Get at details of design (layout, icons, colors)
 +  * Should not think of prototype as part of finished system (no recycling)
 +
 +==== Medium Fidelity? ====
 +
 +  * Somewhere in between.
 +  * High production values, no/limited interaction.
 +  * E.g. Photoshop
 +  * Tests detail of design without commiting.
 +  * Because no functionality, less pressure from users.
 +
 +==== Prototyping & Evaluation ====
 +
 +  * (Early)
 +  * (Low fidelity)
 +  * Rough out on paper
 +  * Cognitive walkthrough
 +  * Formative evaluation
 +  * (Late)
 +
 +See slides.
 +
 +===== Formative Evaluations =====
 +
 +  * Done on low fidelity prototypes.
 +  * Wizard of Oz - smoke and mirrors to simulate working system.
 +  * GOMS and action analysis - uses models to predict certain attributes of prototypes.
 +  * Cognitive walkthroughs.
 +  * Heuristic evaluations - artificial evaluation using a top-ten list of mistakes or good practices.
 +
 +===== Project 2 - Initial Prototypes =====
 +
 +Prepare a prototype that answers two things:
 +  * What is the problem?
 +    * Who are users?
 +    * What are their needs?
 +    * What are constraints?
 +  * What is your solution?
 +    * Present multiple prototypes.
 +    * Sketches, storyboards, mockups.
 +    * Why for each. Pros/cons.
 +
 +===== Human Stuff =====
 +
 +==== Cognitive Processes ====
 +
 +  * Attention
 +  * Perception and recognition
 +  * Memory
 +  * Learning
 +  * Reading, speaking, listening
 +  * Problem-solving, planning, reasoning, decision making
 +
 +==== Senses ====
 +
 +  * Sight, hearing, touch important for design of current interfaces.
 +  * Smell, taste?
 +  * Balance and propioception (where limbs etc. are physically)
 +
 +=== Key Sense Concepts ===
 +
 +  * Absolute threshold
 +    * Thresholds that determine what range you can sense.
 +    * Upper and lower thresholds.
 +  * Signal detection theory
 +    * Ability to tune in/out stimuli.
 +  * Just noticeable difference
 +    * How much change is required before you sense the difference?
 +  * Sensory adaptation
 +    * We react to change.
 +    * Absense of change leads us to loose sensitivity (psychological nystagmus).
 +
 +=== Vision ===
 +
 +  * Visual Angle
 +    * Total: 200 degrees.
 +    * High-res: ~15 degrees.
 +  * Rods
 +    * 120 million.
 +    * B&W
 +    * 1000x more sensitive than cones.
 +  * Cones
 +    * 6-7 million.
 +    * 64% red.
 +    * 32% green.
 +    * 2% blue.
 +  * Phenomena
 +    * Color perception:
 +      * 7-8% males cannot distinguish red from green.
 +      * 0.4% of women.
 +    * Peripheral vision is largely movement oriented.
 +    * Stereopsis:
 +      * (Stereopsis is ability to see in three dimensions.)
 +      * Monocular (size, interposition, perspective, paralax)
 +        * Ability to detect depth with one eye.
 +      * Binocular (retinal disparity, accommodation)
 +        * Ability to detect depth with two eyes.
 +
 +=== Hearing ===
 +
 +  * Capabilities
 +   * Frequency: 20-20,000 Hz
 +   * Loudness: 30 - 100 dB
 +   * Location: 5˚ source & stream separation
 +   * Timbre: Type of sound (lots of instruments)
 +  * Often take for granted how good it is.
 +
 +=== Motor System ===
 +
 +  * Our output system.
 +  * Capabilities
 +   * Range of movement, reach, speed, strength, dexterity, accuracy.
 +   * Workstation/device design.
 +  * Often cause of errors:
 +   * Wrong button.
 +   * Double-click vs. single.
 + * Principles
 +   * Feedback is important.
 +   * Minimize eye movement.
 +
 +==== The Model Human Processor ====
 +
 +  * Classic study from CS perspective of how brain works
 +    * Microprocessor-human analogue using results from experimental psychology.
 +    * Provides a view of the human that fits much experimental data.
 +    * But it is partial model.
 +  * Focus is on a single user interacting with some entity (computer, environment, tool).
 +
 +=== Memory ===
 +
 +  * Perceptual "buffers":
 +    * Brief impressions
 +  * Short-term (working) memory:
 +    * Conscious thought, calculations.
 +    * Different store for visual vs. auditory memory.
 +    * Order of seconds.
 +  * Long-term memory:
 +    * Minutes, hours, days, years, decades.
 +    * Long term, large storage space.
 +    * Access is harder, slower.
 +    * Retrieval depends upon network of associations.
 +    * Memory Structure
 +      * Episodic Memory
 +        * Events and experiences in serial form.
 +        * Helps us recall what occured.
 +      * Semantic memory
 +        * Structured record of facts, concepts, skills.
 +        * One theory says it's like a network.
 +        * Another uses frames & scripts.
 +
 +==== Decision Making Models ====
 +
 +Understanding cognition important because it helps you understand how to teach people.
 +
 +  * Production systems
 +    * If-then rules
 +    * Work like a computer program
 +  * Connectionism (big idea in AI)
 +    * Neural networks
 +    * Hidden Markov models
 +    * Bayesian networks
 +    * Modeled after a network of nodes
 +      * Nodes are factoids or rules.
 +      * Connections between.
 +      * Any time you follow a path that leads to success, strengthen the path.
 +      * Any time you make a mistake, weaken the path.
 +  * Mediated action
 +    * Actions must be interpreted in context
 +    * Tools, setting, culture affect
 +    * Objects "tell" us how to use it
 +    * The way things are shaped and presented affects how people interact with them
 +  * Case-based reasoning
 +    * Learn from experience, reasoning same as memory
 +    * Plans, schemes, and automation
 +    * Take closest matching experience and modify it to meet requirements
 +  * External/embodied cognition
 +    * Emphasizes reflexes and stuff
 +
 +===== Evaluation =====
 +
 +  * Evaluation is part of the design cycle.
 +
 +==== Why evaluate? ====
 +
 +  * If you make a mistake and don't catch it, it'll screw you later.
 +  * If we think of design as iterative process, we need to evaluate whether we're getting better.
 +  * Also, at each stage of design we make assumptions. We need to check whether those assumptions match reality.
 +
 +==== What is evaluation? ====
 +
 +  * Different from requirements gathering:
 +    * Testing a hypothesis.
 +    * Often use different methods, more focused.
 +  * Methods you choose depend on debates:
 +    * Quant. vs. quals.
 +    * Controlled vs. ecological validity
 +    * Cost vs. relevance.
 +
 +==== Steps Involved ====
 +
 +  * Formulate hypothesis.
 +    * Hypothesis = statement of fact.
 +    * Important to have hypothesis for data analysis.
 +  * Design a test plan.
 +    * Picking a method.
 +    * Selecting users.
 +    * Writing out procedure.
 +  * Get IRB permission.
 +  * Deal with users.
 +  * Deal with data.
 +
 +
 +==== Testing Methods ====
 +
 +  * Formative
 +  * Artificial/Controlled
 +    * Isolate variables, level playing field.
 +    * Removes "noise" from data.
 +    * Thoroughly documented.
 +    * Focus **only** on your question.
 +  * Issues:
 +    * Putting people in contrived environment causes changes in how people interact.
 +    * Results from controlled experiments can't be directly compared to real world.
 +
 +==== Hypothesis Testing ====
 +
 +  * Example hypotheses:
 +    * X is better/larger/faster than Y.
 +    * X improved more than Y.
 +
 +  - Specify null hypothesis (H0) and alternative hypothesis (H1).
 +    - Define H1 = true iff H0 = false.
 +  - Select significance level. Typically P = 0.05 or P = 0.10
 +  - Sample population and calculate statistics.
 +  - Calculate probability (p-value) of obtaining a sta...
 +(SEE SLIDES)
 +
 +==== Dealing with Data ====
 +
 +  * Academic honesty key.
 +    * Falsifiability of results.
 +    * Need for meticulous records.
 +      * Keep records unmodified.
 +    * Objectivity.
 +    * Peer review.
 +    * Replication.
 +      * Not done in software design.
 +
 +==== Statistical Significance ====
 +
 +  * Statistical significance means: Two populations differ to a significant extent along some variable.
 +  * Statistical significance does NOT mean noteworthy.
 +  * Typically in either rate of occurance, or the value of some result.
 +    * E.g. group A 2x likely to do well on tests than group B (statistically significant), yet the difference in scores may not be large enough to be significant.
 +
 +==== Significance: Type I and II Errors ====
 +
 +  * What does significance mean?
 +    * Type I: False negative.
 +    * Type II: False positive.
 +  * Set significance to balance risks of type I or II errors:
 +    * When might low type I and high type II (vice versa) be preferable?
 +  * These types of errors may arise from equipment limits, etc.
 +
 +==== Predictive Models ====
 +
 +  * Models used to predict human behavior, responses.
 +  * Stimulus-Response
 +    * Hick's law:
 +      * Decision time to choose among N equally likely alternatives.
 +      * T = Ic log2(n+1)
 +        * Ic = time to recognize each item = 150msec
 +      * Useful for pilot tests.
 +    * Fitt's law.
 +      * Time it takes to select something on screen.
 +      * ID = log2(d/w + 1.0)
 +        * d = distance; w = width of target; ID = index of difficulty
 +  * Cognitive - human as interpreter/predictor - based on Model Human Processor:
 +    * Keystroke Level Model:
 +      * Puts together lots of mini-models, comes up with larger coherent model.
 +      * Assigns times for basic human operations - experimentally verified.
 +      * Based upon MHP.
 +      * Accounts for:
 +        * Keystroking: Tk
 +        * Mouse button press: Tb
 +        * Pointing: Tp
 +        * Hand movement between kbd/mouse: Th
 +        * Drawing straight line segments: Td
 +        * "Mental preparation": Tm
 +        * System response time: Tr
 +
 +==== Within-Subject or Between-Subject Design ====
 +
 +  * Between subjects: Pool using prototype 1, separate pool using prototype 2.
 +    * Clean statistics -- less noise.
 +  * Within-subjects: Same subject uses both prototypes.
 +    * Removes people variations.
 +
 +===== Heuristic Evaluation =====
 +
 +==== Discount Usability Engineering ====
 +
 +  * Cheap
 +    * No special labs/equipment.
 +    * More careful you are, the better it gets.
 +  * Fast
 +    * On order of 1 day to apply.
 +    * Standard usability testing may take a week.
 +  * Easy to use
 +    * Can be taught in 2-4 hours.
 +  * Reliance on discount UE can lead to sloppiness.
 +    * Easy to ignore more thorough evaluation methods.
 +    * Not all you need.
 +
 +==== HE Overview ====
 +
 +  * Developed by Jacob Nielsen.
 +    * Involves a set of guidelines -- heuristics.
 +    * Rules come from real-world experience.
 +  * Helps find usability problems in UI design.
 +  * Small set (3-5) of evaluators examine UI.
 +    * Independently check for compliance with usability principles (heuristics).
 +    * Different evaluators will find different problems.
 +    * Evaluators only communicate afterward; findings are then aggregated.
 +  * Can perform on working UI or sketches.
 +  * Most important ideas:
 +    * Independent analysis.
 +    * Performed on sketches or UI.
 +
 +==== Process ====
 +
 +  * Evaluators go through UI several times.
 +    * Inspect various dialogue elements.
 +    * Compare with list of principles.
 +    * Consider other principles/results that come to mind.
 +  * Usability principles:
 +    * Nielsen's "heuristics".
 +    * Supplementary list of category-specific heuristics.
 +      * May come from competitive analysis & user testing of existing products.
 +  * Fixes for violations may be suggested by heuristics.
 +
 +==== Nielsen's Original 10 Heuristics ====
 +
 +  * Simple & natural dialog
 +  * Speak user's language
 +  * Minimize user's memory load
 +  * Consistency
 +  * Feedback
 +  * Clearly marked exits
 +  * Shortcuts
 +  * Precise & constructive error messages
 +  * Prevent errors
 +  * Help and documentation
 +
 +==== Heuristics -- Revised Set ====
 +
 +=== Visibility of System Status ===
 +
 +  * Keep user informed about what is going on.
 +  * Example: Pay attention to response time.
 +    * 0.1 sec: No special indicator needed.
 +    * 1.0 sec: User tends to lose track of data.
 +    * 10 sec: Max. duration if user to stay focused on action.
 +    * For longer delays, use progress bars.
 +
 +=== Match between system and real world ===
 +
 +  * Speak user's language.
 +  * Follow real world conventions.
 +
 +=== Consistency & Standards ===
 +
 +=== Aesthetic and minimalist desgin ===
 +
 +  * No irrelevant info in dialogs.
 +
 +==== HE vs. User Testing ====
 +
 +  * HE much faster.
 +  * HE doesn't require interpreting user's actions.
 +  * User testing far more accurate.
 +    * Takes into account actual users and tasks.
 +    * HE may miss problems and find false positives.
 +  * Good to alternate between HE and user testing.
 +    * Find different problems.
 +    * Don't waste participants.
 +
 +==== HE Results ====
 +
 +  * Single evaluator achieves poor results.
 +    * Only finds 35% of usability problems.
 +  * 5 evaluators find ~75% of problems.
 +    * If they work as team, it's back down to 35%.
 +  * Why not more evaluators?
 +    * Adding evaluators costs more.
 +    * Many more evaluators won't find many more problems.
 +
 +===== Evaluation (2) & Wrap-Up =====
 +
 +==== Evaluation Pt. 2 ====
 +
 +=== Usability Testing: The Usability Lab ===
 +
 +  * A specially designed room for conducting controlled experiments observing a task.
 +  * Cameras, logging systems, people track what users do.
 +  * Good lab costs $$$.
 +
 +== Observation Room ==
 +
 +  * Three cameras capture subject, subject's monitor, and composite picture.
 +  * One-way mirror plus angled glass captures light and isolates sound between rooms.
 +  * Room for several observers.
 +  * Digital mixer for mixing of input images and recording to media.
 +
 +== Other Capture - Software ==
 +
 +  * Modify software to log user actions.
 +  * Can give time-stamped keypress/mouse events -- sync with video
 +  * Commercial software available ($$$)
 +  * Two problems:
 +    * Too low level, want higher level events
 +    * Massive amount of data; need analysis tools
 +
 +== Complimentary Methods ==
 +
 +  * Talkaloud protocols
 +  * Pre/post surveys
 +  * Participant screening/normalization
 +  * Compare results to existing benchmarks