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Test, Test, & Retest

Test, Test, & Retest

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Test, Test, & Retest

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  1. Test, Test, & Retest

  2. Step 14TEST, TEST, AND RETEST Step 14 Overview • Identifying the purpose and scope of testing • Understanding the importance of testing • Developing a prototype • Developing the right kind of test plan • Designing a test to yield relevant data • Soliciting, selecting, and scheduling participants • Providing the proper test facility • Conducting tests and collecting data • Analyzing the data and generating recommendations • Modifying the prototype as necessary • Testing the system again • Evaluating the working system

  3. Step 14USABILITY Dimensions • Effective • Efficient • Engaging • Error tolerant • Easy to learn

  4. Step 14PURPOSE OF USABILITY TESTING • Establish communication bridge between developers and users • Developer learns about user’s goals, perceptions, questions, and problems • User exposed to capabilities of system early on, before design is solidified • Evaluate a product • Validate design decisions • Identify potential problems early in design • Enable comparison of alternate versions of a design element • Assess how well user needs and expectations are met • Prevent embarrassment resulting from things “slipping through the cracks”

  5. Step 14IMPORTANCE OF USABILITY TESTING • Developers and users possess different models • Developer’s intuitions are not always correct • There is no average user • It’s impossible to predict usability from appearance • Design standards and guidelines are not sufficient • Informal feedback is inadequate • Products’ built-in pieces almost always have system-level inconsistencies • Problems found late more difficult and expensive to fix • Problems fixed during development mean reduced support costs later • Advantages over a competitive product can be achieved

  6. Step 14SCOPE OF TESTING Types of Tests • Exploratory • Explore prototype interface design features • Gather feedback on preliminary designs • Verify assumptions derived during requirements determination • Assessment • Establish how well user tasks are supported • Determine what usability problems may exist • Comparative • Compare two or more design alternatives • Validation • Ascertain whether a usability objective is achieved

  7. Step 14PROTOTYPES • Vehicles for • Exploration • Communication • Evaluation • Purpose • Obtain user input in design • Provide feedback to designers • Roles • Communication not accuracy or thoroughness • Enables design to be better visualized • Provides insights into how the software will look and work • Aids in defining tasks, their flow, the interface itself, andits screens

  8. Step 14PROTOTYPES Kinds • Hand sketches and scenarios • Screen sketches created by hand • Interactive paper prototypes • Interface components constructed of commonpaper technologies • Programmed facades • Examples of finished dialogs and screens for some important aspects of the system • Prototype-oriented languages • An example of finished dialogs and screens for some important aspects of the system

  9. Step 14PROTOTYPES Hand Sketches and Scenarios • Description • Screen sketches created by hand • Focus is on design, not interface mechanics • A low-fidelity prototype • Advantages • Can be used very early in the development process • Suited for use by entire design team • No large investment of time and cost • No programming skill needed • Easily portable • Fast to modify and iterate • A rough approximation often yields more substantive critical comments • Easier to comprehend than functional specifications • Can be used to define requirements

  10. Step 14PROTOTYPES Hand Sketches and Scenarios (Continued)‏ • Disadvantages • Only a rough approximation • Limited in providing an understanding of navigation and flow • A demonstration, not an exercise • Driven by a facilitator, not the user • Limited usefulness for a usability test • A poor detailed specification for writing the code • Usually restricted to most common tasks

  11. Step 14PROTOTYPES Hand Sketch Creation Process • Sketch (storyboard) the screens while determining: • The source of the screen’s information • The content and structure of individual screens • The overall order of screens and windows • Use an erasable medium • Sketch the screens needed to complete each task • Try selected metaphors and change as necessary • Storyboard common/critical/frequent scenarios first • Follow from beginning to end • Then, go back and build in exceptions • Don’t get too detailed; exact control positioning is not important, just overall order and flow • Sketch storyboard as a team, including at least one user • Develop online prototypes only when everyone agrees that a complete set has been satisfactorily sketched

  12. Step 14PROTOTYPES Interactive Paper Prototypes • Description • Interface components (menus, windows, and screens) constructed of common paper technologies (Post-It notes, transparencies)‏ • Components are manually manipulated to reflect the dynamics of the software • A low-fidelity prototype • Advantages: • More illustrative of program dynamics than sketches • Can be used to demonstrate the interaction • Otherwise, generally the same as for hand-drawn sketches and scenarios • Disadvantages: • Only a rough approximation • A demonstration, not an exercise • Driven by a facilitator, not the user • Limited usefulness for usability testing

  13. Step 14PROTOTYPES Programmed Facades • Description • Examples of finished dialogs and screens for some important aspects of the system • Created by prototyping tools • Medium-fidelity to high-fidelity prototypes • Advantages • Provide detailed specification for writing code • A vehicle for data collection • Disadvantages • May solidify the design too soon • May create the false expectation that the “real thing” is only a short time away • More expensive to develop • More time-consuming to create • Not effective for requirements gathering • Not all of the functions demonstrated may be used • Not practical for investigating more than two or three approaches

  14. Step 14PROTOTYPES Prototype-Oriented Languages • Description • An example of finished dialogs and screens for some important aspects of the system • Created through programming languages that support the actual programming process • A high-fidelity prototype • Advantages • May include the final code • Otherwise, generally the same as those of programmed facades • Disadvantages • Generally the same as for programmed facades

  15. Step 14PROTOTYPES Fidelity • Prototype fidelity seems to have no impact on the identification of usability problems • Combinations of these prototypes should be used throughout the entire system development cycle

  16. Step 14TESTS A tool to measure something, including: • Conformance with a requirement • Conformance with guidelines for good design • Identification of design problems • Ease of system learning • Retention of learning over time • Speed of task completion • Speed of need fulfillment • Error rates • Subjective user satisfaction

  17. Step 14KINDS OF TESTS • Guidelines and standards review • A review of the interface in terms of an organization’s standards and design guidelines • Heuristic evaluation • A detailed evaluation of a system by interface design specialists to identify problems • Cognitive walkthroughs • Reviews of the interface in the context of tasks users perform • Think-aloud evaluations • Users perform specific tasks while thinking aloud • Usability test • An interface evaluation under real-world conditions • Classic experiments • An objective comparison of two or more prototypes identical in all aspects except for one design issue • Focus groups • A discussion with users about interface design prototypes or tasks

  18. Step 14KINDS OF TESTS Guidelines and Standards Review • Description: • A review of the interface in terms of an organization’s standards and design guidelines • Advantages: • Can be performed by developers • Low cost • Can identify general and recurring problems • Particularly useful for identifying screen design and layout problems • Disadvantages: • May miss severe conceptual, navigation, and operational problems



  21. Step 14KINDS OF TESTS Heuristic Evaluation • Description: • A detailed evaluation of a system by interface design specialists to identify problems • Advantages: • Easy to do • Relatively low cost • Does not waste user’s time • Can identify many problems • Disadvantages: • Evaluators must possess interface design expertise • Evaluators may not possess an adequate understanding of the tasks and user communities • Difficult to: • Identify systemwide structural problems • Uncover missing exits and interface elements • Identify most important of all identified problems • Does not provide systematic way to generate solutions to problems

  22. Step 14KINDS OF TESTS Heuristic Evaluation Process • Guidelines: • Use 3 to 5 expert evaluators • Choose knowledgeable people • Familiar with the project situation • Possessing a long-term relationship with the organization • Experienced • Preparing the session: • Select evaluators • Prepare or assemble: • Project overview • Checklist of heuristics • Provide briefing to evaluators to: • Review the purpose of the evaluation session • Preview the evaluation process • Present the project overview and heuristics • Answer any evaluator questions • Provide any special evaluator training that may be necessary

  23. Step 14KINDS OF TESTS Heuristic Evaluation Process (Continued)‏ • Conducting the session: • Have each evaluator review the system alone • The evaluator should: • Establish own process or method of review • Provide usage scenarios, if necessary • Compare findings with usability principles list • Identify any other relevant problems / issues • Make at least two passes through the system • Detected problems should be related to the specific heuristics they violate • Comments are recorded either: • By evaluator • By observer • The observer may answer questions and provide hints • Restrict the length of the session to 2 hours

  24. Step 14KINDS OF TESTS Heuristic Evaluation Process (Continued)‏ • After the session: • Hold a debriefing session including observers and design team members where: • Each evaluator presents problems detected and the heuristic it violated • A composite problem listing is assembled • Design suggestions for improving the problematic aspects of system are discussed • After the debriefing session: • Generate a composite list of violations as a ratings form • Request evaluators to assign severity ratings to each violation • Analyze results and establish a program to correct violations and deficiencies

  25. Step 14KINDS OF TESTS Research-Based Set of Heuristics (Table 14.3)‏ • Automate unwanted workload • Free cognitive resources for high-level tasks • Eliminate mental calculations, estimations, comparisons, and unnecessary thinking • Reduce uncertainty • Display data in a manner that is clear and obvious • Fuse data • Reduce cognitive load by bringing together lower-level data into a higher-level summation • Present new information with meaningful aids to interpretation • Use a familiar framework, making easier to absorb • Use everyday terms, metaphors, and so on • Use names that are conceptually related to functions • Context-dependent • Attempt to improve recall and recognition

  26. Step 14KINDS OF TESTS Research-Based Set of Heuristics (Table 14.3) (Continued) • Group data in consistently meaningful ways to decreasesearch time • Limit data-driven tasks • Reduce the time needed to assimilate raw data • Make appropriate use of color and graphics • Include in the displays only that information needed by a userat a given time • Allow users to remain focused on critical data • Exclude extraneous information that is not relevantto current tasks • Provide multiple coding of data where appropriate • Practice judicious redundancy • To resolve the conflict between heuristics 6 and 8 From Gerhardt-Powals (1996)‏

  27. Step 14KINDS OF TESTS Possible Web Page Heuristics (Table 14.4) • Speak the user’s language • Use familiar words, phrases, and concepts • Present information in a logical and natural order • Be consistent • Indicate similar concepts through identical terminologyand graphics • Adhere to uniform conventions for layout, formatting, typefaces, labeling, and so on • Minimize the user’s memory load • Take advantage of recognition rather than recall • Do not force users to remember key information across documents

  28. Step 14KINDS OF TESTS Possible Web Page Heuristics (Table 14.4) (Continued) • Build flexible and efficient systems • Accommodate a range of user sophistication and diverse user goals • Provide instructions where useful • Lay out screens so that frequently accessed informationis easily found • Design aesthetic and minimalist systems • Create visually pleasing displays • Eliminate irrelevant or distracting information • Use chunking • Write materials so that documents are short and containonly one topic • Do not force the user to access multiple documents to complete a single thought

  29. Step 14KINDS OF TESTS Possible Web Page Heuristics (Table 14.4) (Continued) • Provide progressive levels of detail • Organize information hierarchically, with more general information appearing before more specific • Encourage the user to delve as deeply as needed, but tostop whenever sufficient information has been obtained • Give navigational feedback • Facilitate jumping between related topics • Allow the user to determine current position in document structure • Make it easy to return to an initial state • Don’t lie to the user • Eliminate erroneous or misleading links • Do not refer to missing information From Levi and Conrad (1996) ‏

  30. Nielsen’s HE ( • 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 The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order. • 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 extended dialogue. Support undo and redo. • Consistency and standards Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.

  31. Nielsen’s HE ( • Error prevention Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action. • 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. Instructions for use of the system should be visible or easily retrievable whenever appropriate. • 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. Allow users to tailor frequent actions. • 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 and diminishes their relative visibility.

  32. Nielsen’s HE ( • Help users recognize, diagnose, and recover from errors Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution. • 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. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

  33. Xerox HE Checklist

  34. Step 14KINDS OF TESTS Cognitive Walkthroughs • Description: • Reviews of the interface in the context of tasks users perform • Advantages: • Allow a clear evaluation of the task flow early in the design process • Do not require a functioning prototype • Low cost • Can be used to evaluate alternate solutions • Can be performed by developers • More structured than a heuristic evaluation • Useful for assessing “exploratory learning” • Disadvantages: • Tedious to perform • May miss inconsistencies and general and recurring problems

  35. Step 14KINDS OF TESTS Cognitive Walkthroughs (Continued) • Guidelines: • Needed to conduct the walkthrough are: • General description of proposed system users and their relevant knowledge • Specific description of one or more core or representative tasksto be performed • List of correct actions to complete each task • Review: • Several core or representative tasks across a range of functions • Proposed tasks of particular concern • Developers must be assigned roles of: • Scribe to record results of the action • Facilitator to keep the evaluation moving • Start with simple tasks • Don’t get bogged down demanding solutions • Limit session to 60 to 90 minutes

  36. Step 14KINDS OF TESTS Think-Aloud Evaluations • Description: • Users perform specific tasks while thinking aloud • Comments are recorded and analyzed • Advantages: • Utilizes actual representative tasks • Provides insights into the user’s reasoning • Disdvantages: • May be distracting and unnatural for participants • Can slow participants thought processes • Can be exhausting for participant • Guidelines: • Develop: • Several core or representative tasks • Tasks of particular concern • Limit session to 60 to 90 minutes

  37. Step 14KINDS OF TESTS Usability Test • Description: • An interface evaluation under real-world or controlled conditions • Measures of performance are derived for specific tasks • Problems are identified • Advantages: • Utilizes an actual work environment • Identifies serious or recurring problems • Disadvantages: • High cost for establishing facility • Requires test conductor with interface expertise • Emphasizes first-time system usage • Poorly suited for detecting inconsistency problems

  38. Step 14KINDS OF TESTS Performance and Process Measures • Performance Data • Focuses on how well users can do their tasks • Completion rates • Completion times • Error rates • Process Data • Comprised of measures about what users are doing during task completion • Participant's self reports • Observation of participant behavior • Eye movement tracking

  39. Step 14KINDS OF TESTS Classic Experiments • Description: • An objective comparison of two or more prototypes identicalin all aspects except for one design issue • Advantages: • Objective measures of performance are obtained • Subjective measures of user satisfaction may be obtained • Disadvantages: • Requires a rigorously controlled experiment to conduct the evaluation • The experiment conductor must have expertise in setting up, running, and analyzing data collected • Requires creation of multiple prototypes

  40. Step 14KINDS OF TESTS Classic Experiments (Continued) • Guidelines: • State a clear and testable hypothesis • Specify a small number of independent variables to be manipulated • Carefully choose the measurements • Judiciously select study participants and carefully or randomly assign them to groups • Control for biasing factors • Collect the data in a controlled environment • Apply statistical methods to data analysis • Resolve the problem that led to conducting the experiment

  41. Step 14KINDS OF TESTS Focus Groups • Description: • A discussion with users about interface design prototypesor tasks • Advantages: • Useful for: • Obtaining initial user thoughts • Trying out ideas • Easy to set up and run • Low cost • Disadvantages: • Requires experienced moderator • Not useful for establishing: • How people really work • What kinds of usability problems people have

  42. Step 14KINDS OF TESTS Focus Groups (Continued) • Guidelines: • Restrict group size to 8 to 12 • Limit to 90 to 120 minutes in length • Record session for later detailed analysis

  43. Step 14CHOOSING A TESTING METHOD Usability Test vs. Heuristic Evaluation • Research concludes that both are effectiveat different times in the design process andshould be utilized • Heuristic reviews should be applied first or earlyin the design process to identify simpler problems • Usability testing should be applied later in the designprocess to identify more complex problems

  44. Step 14CHOOSING A TESTING METHOD Concurrent vs. Retrospective User Comments • Concurrent • Participants verbalize their observations and comments during the test • Retrospective • Participants verbalize their observations and comments after test completion • Study Results • There are no differences in the majority of the comments usingeither method • Concurrent does not appear to slow down the participants or cause more errors • Valid comments can be collected up to 24 hours after the test • Participants tend to comment on successes, not “struggles” • Concurrent are better for certain design problems such as link naming • Retospective are more valuable for helping resolve complex issues

  45. Step 14DEVELOPING & CONDUCTING A TEST TheTest Plan • Define the scope of the test • Define the purpose of the test • Performance goals • What the test is intended to accomplish • Create a test timetable • Define the test methodology • Type of test to be performed • Test limitations • Developer participants • Develop scenarios to satisfy the test’s purpose • Select test Participants • Identify and schedule the test facility or location • Run a pilot test

  46. Step 14DEVELOPING & CONDUCTING A TEST Things to Test in Web Site Design (Table 14.6) • All the browsers, servers, and monitors used • Different dial-up speeds • Navigation design • Visual design style • Content legibility and readability • Backgrounds and color • Graphics and icons • Page breaks • Page printing • Accessibility