ISE 164 Human-Computer Interaction

Design Criteria

Who the users are, what activities are being carried out, where the interaction is taking place

WIMP

Windows, Icons, Menus, Pointers

Human Information Processing

The psychological approach that attempts to identify what occurs during the various stages (attention, perception, short-term memory) of processing information

Problem space

The set of possible pathways to a solution considered by the problem solver.

Recognition

-Information gives knowledge that it has been seen before -Less complex and less difficult than recall - information is the cue

Multimodal interface

-form of human-computer interaction using multiple forms of interaction -blurring of physical and virtual -ex: touch, speech, eyeline movement, gestures

Norman's 7 Stages

1. Establishes goal 2. Formulates intention 3. Specifies actions 4. Executes actions 5. Perceives system state 6. Interprets system state 7. Evaluates system state

Performance

A dimension of UX; are users succeeding? How hard is it and how long does it take?

Impact

A dimension of UX; did users enjoy themselves, will they remember this, will they come back

Behavior

A dimension of UX; how users are trying to something and what features they're using

Intent

A dimension of UX; what users are trying to do and what they want to do

Usability testing

A method by which users of a Web site or other product are asked to perform certain tasks in an effort to measure the product's ease-of-use and the user's perception of the experience.

Natural language

A method of computer communication that is familiar to the user. e.g. speech recognition or typing Problems: vague, ambiguous, difficult to do well

Controlled processes

A process is controlled when the brain works consciously. -Has limited capacity and requires attention and conscious control -Can be changed easily

High Fidelity Prototype

A prototype which is quite close to the final product, with lots of detail and a good indication of the final proposed aesthetics and functionality.

Waterfall Development

A series of steps in which a software system trickles down from analysis to design to implementation. -Slow process that cannot backtrack

Agile Development

A software development methodology that delivers functionality in rapid iterations, measured in weeks, requiring frequent communication, development, testing, and delivery.

Early development

A stage of usability testing that is maybe the best time to do testing because not too much progress has been made, so the product is still easy to alter

Mid development

A stage of usability testing where the most common/important tasks are evaluated. -Participants are asked to express their strategies and experiences -Key benefit: help evaluate realistic tasks to determine how well the product was designed

Late development

A stage of usability testing where the product is finished, coded, in beta or alpha testing, and almost ready to release -Can now identify specific problems -Validation testing can occur, measuring metrics

GUI (Graphical User Interface)

A type of interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation.

Lab studies

A type of study done in a controlled environment Advantages: specialist equipment available, uninterrupted environment Disadvantages: lack of context, difficult to observe several users cooperating

Command line interface

A way of expressing instructions to the computer directly -Suitable for repetitive tasks -Better for expert users than novices -Offers very quick, direct access to system functionality -Command names/abbreviations should be meaningful

Long term memory

Acts as a repository for all our knowledge -Slow access - 1/10 of a second -Slow decay, if any -Huge or unlimited capacity

SSL Certificate

An electronic document that confirms the identity of a website or server and verifies that a public key belongs to a trustworthy individual or company. Displays a green lock icon

stimulus identification

As stimulus contrast/intensity increases, reaction time decreases asymptotically

Automatic processes

Brain works on autopilot, without conscious thought. -Not limited by the capacity of the brain, does not require attention -Very difficult to change

Visibility

Defined as keeping users informed about what is going on, through appropriate feedback within reasonable time

Accessibility

Degree to which a product is usable by as many people as possible

Consistency

Design interfaces to have similar operations and use similar elements for similar tasks Main benefit is that interfaces are easier to learn and use

ISO Usability Standard 9241

Effectiveness, efficiency, and satisfaction are key tenets of this

Manipulating

Exploits users' knowledge of how they move and manipulate in the physical world

Direct manipulation

Instead of typing in esoteric syntax commands into a terminal, use a mouse cursor to point and click to perform actions immediately

Heuristic evaluation

Interface specialists examine the UI by comparing it to a set of heuristics or principles for interface design to determine its usability Advantages: relatively inexpensive and fast, performed at any phase of product development, identifies many problems Disadvantages: relies on analysis rather than user testing, relies on judgment of the evaluator and their experience

Low Fidelity Prototype

Low cost, illustrated design or concept usually sketched on paper or created as flat images.

Mistake

May not even have right goal, incorrect formulation of action, incorrect action Requires user to have a better understanding of the system

Scripts

Models of stereotypical information required to interpret the situation, and have elements that can be instantiated with values

Hick-Hyman Law

More choices leads to a slower reaction time; logarithmic relationship

Usability Metrics

Numerical ways to quantify success

Cognitive walkthrough

Performed by experts in cognition, this is a technique used to evaluate a computer interface or a software program by breaking down and explaining the steps that a user will take to accomplish a task.

Query Interface

Q/A interface -User led through interaction via series of questions -Suitable for novice users but restricted functionality -Often used in information systems

Simon effect

Reactions are faster and more accurate when the stimulus occurs in the same relative location as the response, even if the stimulus location is irrelevant to the task

Perception

Refers to how information is acquired from the world and transformed into experiences

Miller's Magic Number

Refers to the pieces of info a human brain can hold at once in short term memory: 7 +/- 2

Affordances

Refers to the properties of objects, determines what kind of operation and manipulation can be done for a particular object. e.g. Doors afford opening, chairs afford sitting, comfort

Attention

Selecting things to concentrate on at a point in time from the mass of stimuli around us

Feedback

Sending info back to the user about what has been done -Includes sound, highlighting, animation, and combinations of these -Can be visual, auditory, tactile -Should be compatible with the principles of direct manipulation

Field studies

Studies in which people's behavior is observed in a natural setting Advantages: natural environmental, context retained, enables longitudinal studies Disadvantages: distractions, noise

Mental image

Symbolic; a figurative abstraction of the object e.g. Imagining the word Elephant rather than a picture of an elephant

Fitt's Law

There is a logarithmic relationship between reaction time, size of the target, and distance between the pointer and center of the target

Slip

Understand system and goal, correct formulation of action, incorrect action Requires better interface design

Persona

User archetype you can use to help guide decisions throughout the design process

User profiling

When performing ___________, consider the task, level of expertise, usage/role, tools, expectation, roles

Structured

__________ interviews are replicable but not rich

Unstructured

___________ interviews are rich but not replicable

Evaluation techniques

____________ include expert-based, review-based, and cognitive walkthrough

Echoic memory

a momentary sensory memory of auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds

Iconic memory

a momentary sensory memory of visual stimuli; a photographic or picture-image memory lasting no more than a few tenths of a second

Conceptual model

a verbal or graphical explanation for how a system works or is organized Benefits include orientation, open-minded, common ground

Recall

information reproduced from memory that can be assisted by cues, such as categories or imagery

Proximity (Gestalt Principle)

objects physically close to each other tend to be perceived as unified wholes

Observational methods

procedures for systematically watching behavior in order to summarize it for scientific analysis Includes think aloud, cooperative evaluation, protocol analysis, automated analysis

Episodic memory

serial memory of events, experiences

Semantic memory

structured memory of facts, concepts, skills

Cryptography

the art of protecting information by transforming it into an unreadable format, called cipher text

Information Architecture

the design and structure of an information system e.g. books have table of contents, chapters, titles, paragraphs, and sentences

Ethnography

the scientific description of the customs of individual peoples and cultures, includes participant observation, interviews, and culture immersion

Closure (Gestalt Principle)

the tendency to complete figures that are incomplete

Continuity (Gestalt Principle)

we perceive smooth, continuous patterns rather than discontinuous ones

Similarity (Gestalt Principle)

when we perceive an assortment of objects, we tend to group similar objects together