Web Usability

Help and documentation

Even though it is better if the system can be used without documentation it may be necessary to provide help and documentation.

Conceptualizing

Formulate a model, what kind of interface metaphor will be appropriate, what kind of interaction modes and styles to use

same participants

all participants appear in both conditions

Wireframe

bare bones depiction of all the components of a page and how they fit together

interface metaphors

component of a conceptual model that is instantiated at the interface, Exploits the user's familiar knowledge, helping them to understand the unfamiliar.

Interaction Types

instructing, conversing, manipulating, exploring

Recognition rather than recall

minimize the user's memory load by making objects actions and options visible. The user should not have to remember information from one part of the dialogue to another.

Matched participants

participants are matched in pairs

Controlled usability testing

recording performance of typical users doing typical tasks. The users are observed and timed. Simple repetitive tasks with same conditions for every participant

Usability

"The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction. " Defined by Learnability, Efficiency, Memorability, Errors, Satisfaction

Conceptual model

"a high-level description of how a system is organized and operates" " enables designers to straighten out their thinking before they start laying out their widgets

Seven Stages of action

1. Form the goal 2. Plan the action 3. Specify an action sequence 4. Perform the action sequence 5. perceive the state of the world 6. Interpret the perception 7. Compare the outcome with the goal

Shneiderman'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

Heuristic evaluation

1. Visibility of system status 2. Match between system and the real world 3. User control and freedom 4. Consistency and standards 5. Error prevention 6. Recognition rather than recall 7. Flexibility and efficiency of use 8. Aesthetic & minimalist design 9. Help users recognize, diagnose, and recover from errors 10. Help and documentation.

Prototype

A concrete but partial representation of a system design, a small scale model

Flexibility and efficiency of use

Accelerators unseen by the novice user may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users.

Manipulating

Acting upon virtual objects ex: Dragging selecting and zooming

Norman's principles of design

Affordances, Signifiers, Mappings, Feedback, Constraints

Gulf of execution

Amount of effort that the person must make to determine how to use the device and what actions or operations are possible

Gulf of evaluation

Amount of effort that the person must make to interpret the physical state of the device and determine how well the expectations and intentions have been met.

Error prevention

Even better than good error messages is a careful design which prevents a problem from occurring in the first place.

Analytics

Collecting data about users activities on a website or product

Feedback

Communicating the results of an action

Consistency

Design interfaces to have similar operations and use similar elements for similar tasks.

Aesthetic and minimalist design

Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information.

User Centered

Early focus on users and tasks: directly studying cognitive behavioral and attitudinal characteristics, empirical measurement: users reactions and performance to scenarios, and iterative design

Data gathering methods

Interviews, focus groups, questionaires/surveys

Reduce short term memory load

Literally obvious

Prevent Errors

Make error messages specific positive in tone and constructive. Try to Ensure correct actions. Allow for reversal of actions as much as possible

Exploring

Not super applicable, users moving through virtual or physical environments

Affordances

Possible interactions between people and the environment. Allows for desired actions to be possible ex: chair affords sitting but may also afford lifting depending on chair

Discoverability

Possible to determine what actions are possible and the current state of the device.

fitts law

Predictive model of human movement. It predicts that the time to point at an object using a device is a function of the distance from the target object and the objects size

3 categories of ser

Primary: frequent and hands on, secondary: occasional or via someone else, and tertiary: affected by its introduction or will influence its purchase

Vertical compromise

Provide a lot of detail for only a few function

Predictive model

Provide a way of evaluating products or desins without directly involving users

Horizontal compromise

Provide a wide range of functions but with little detail

Constraints

Providing physical, logical, semantic, and cultural constraints guides actions and eases interpretation. Helps prevent user from selecting incorrect options

Universal usability

Recognize the needs of diverse users and design for plasticity. Novice features as well as shortcuts for experts.

Mapping

Relationship between the elements of two sets of things

Closure

Sequence of actions should be organized into groups with beginning middle and end. Clear confirmation when an action is completed

Cognitive walkthrough

Set tasks and for each task identify optimal action sequence

High-fidelity prototype

Similar system/software/material to the final product, nearly done basically.

Conversing

Simulates the user having a conversation with another human

Different participants design

Single group of participants are allocated randomly to the experimental conditions

Claim

Stating something is true when it still open to question

Live experiments

Summative evaluation method that involves comparing two or more designs to see which one performs better

Assumption

Taking something for granted when it needs further investigation

Experiment

Test hypotheses to discover new knowledge by investigating the relationship between two or more variables. Usability testing is applied experimentation

Utility

The design's functionality: does it do what users need?

Signifiers

The signaling component of affordances, they need to be perceivable and discoverable.

Visibility of system status

The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

Match between system and the real world

They system should speak the users' language, with words phrases and concepts familiar to the user, rather than system oriented terms.

Useful

Usability + Utility

Approaches to design

User centered, activity centered, systems, and genius design

instruction

User instructs the system and tells it what to do

User control and freedom

Users often choose system functions by mistake and will need a clearly marked emergency exit to leave the unwanted state without having to go through an extend dialogue.

Good design

Users should be involved through development of the project, specific usability and ux goals need to be identified at the beginning, iteration is needed.

Internal locus of control

Users should get the sense that they are in charge of the interface, and it should respond to the user's actions.

Consistency and standards

Users should not have to wonder whether different words situations or actions mean the same thing.

Low-fidelity prototype

Uses a medium which is unlike the final medium something like a paper sketch or a story board

Design

Who are the users? What activities are being carried out? Where is the interaction taking place?

Help users, recognize, diagnose and recover from errors

error messages should be expressed in plain language precisely indicate the problem and constructively suggest a solution

Three basic activities of design

establishing reqirements, generating alternatives or prototyping, and evalutating

Rapid iterative testing and eval

formative method to quickly address issues that prevented participants from proceeding. Identify any large usability issue and create a solution to which an updated prototype will be created so a new test can begin