HCI Part 2 and 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

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