HCI Part 2and Testing

Session 9

INFM 718N

Web-Enabled Databases

Agenda

• Finishing up HCI

• Planning for weekly status reports

• Team meetings

• Testing

Query Formulation Interaction Styles

• Command Language

• Form Fill-in

• Menu Selection

• Direct Manipulation

• Natural Language

Credit: Marti Hearst

Form-Based Query Specification (Melvyl)

Credit: Marti Hearst

Form-based Query Specification (Infoseek)

Credit: Marti Hearst

Starfield

Constructing Starfield Displays

• Two attributes determine the position– Can be dynamically selected from a list

• Numeric position attributes work best– Date, length, rating, …

• Other attributes can affect the display– Displayed as color, size, shape, orientation, …

• Each point can represent a cluster

Dynamic Queries:• IVEE/Spotfire/Filmfinder (Ahlberg &

Shneiderman 93)

Putting It All Together

• http://www.philipglass.com/

Color

• Design for monochrome displays– Provides assured access for color blind users

• Add muted colors where they help– Useful for rapid recognition of categories– Limit to 4 colors per screen (7 per application)

• Pay attention to readability– “Similar” colors look different on another display– Different systems may have different defaults

Size

• Don’t make icons too small– Fitts’ Law: Time = f(distance, size)

• Size can be used to illustrate quantity– Scale size coding by at least 1.5

• No more than 4 font sizes

Animation• Drill down

– Mouseover tool tips, menu expansion

• Illustration– Change over time, icon behavior (on mouseover)

• Display space reuse– Ticker tape, slide show

• Visible transitions • Attention management (once!)

Ben’s “Seamless Interface” Principles• Informative feedback• Easy reversal• User in control

– Anticipatable outcomes– Explainable results– Browsable content

• Limited working memory load– Query context– Path suspension

• Alternatives for novices and experts– Scaffolding

Doug’s Synergistic Interaction Principles• Interdependence with process

– Co-design with search strategy– Importance of response time

• System initiative– Guided process– Exposing the structure of knowledge

• Support for reasoning– Meaningful dimensions– Representation of uncertainty

• Synergy between querying and browsing– Strength of language

• Easily learned– Familiar metaphors (timelines, ranked lists, maps)

Status Reports

• Progress to date

• Lessons learned

• Things you would like advice/ideas on

Types of Errors• Syntax errors

– Detected at compile time

• Run time exceptions– Cause system-detected failures at run time

• Logic errors– Cause unanticipated behavior (detected by you!)

• Design errors– Fail to meet the need (detected by stakeholders)

Types of “Testing”

• Design walkthrough– Does the design meet the requirements

• Code walkthrough– Does the code implement the requirements?

• Functional testing– Does the code do what you intended?

• Usability testing– Does it do what the user needs done?

Functional Testing

• You can’t test every possibility– So you need a strategy

• Several approaches– Object-level vs. system-level– Black box vs. white box– Ad-hoc vs. systematic– Broad vs. deep

• Choose a mix that produces high confidence

Usability Testing

• Define one or more scenarios– Based on the requirements (not your design!)– Focus only on implemented functions

• Provide enough training to get started– Usually with a little supervised practice

• Banish pride of authorship– Best to put programmers behind one-way glass!

• Record what you see– Notes, audiotape, videotape, key capture