Chapter 11 An Evaluation Framework Group 4 Tony

Chapter 11: An Evaluation Framework Group 4: Tony Masi, Sam Esswein, Brian Rood, & Chris Troisi

Introduction n Evaluation helps ensure that product meets the users’ needs Recall Hutch. World & Olympic Messaging System (OMS) – chapter 10 What to evaluate? n n usability user experience

Chapter Goals n n Key concepts & terms to discuss evaluation Description of evaluation paradigms & techniques Conceptual, practical, and ethical issues DECIDE framework for evaluation

Evaluation Paradigms n n Key terms- evaluation paradigms, user studies 4 core evaluation paradigms n n “Quick and dirt” evaluation Usability testing Field Studies Predictive Evaluation

Key Terms User studies involve looking at how people behave in their natural environments, or in the laboratory, both with old technologies and with new ones. Evaluation Paradigm is the set of beliefs which guide any type of evaluation

“Quick and Dirty” n n n Quick & Dirty evaluation describes the common practice in which designers informally get feedback from users or consultants to confirm that their ideas are inline with users’ needs and are liked. Quick & Dirty evaluations are done any time. The emphasis is on fast input to the design process rather than carefully documented findings.

Usability testing n n n Usability testing involves recording typical users’ performance on typical tasks in controlled settings. As the users perform these tasks they are watched & recorded on video & their key presses are logged. This data is used to calculate performance times, identify errors & help explain why the users did what they did. User satisfaction questionnaires & interviews are used to elicit users’ opinions. n Recall Hutch. World and OMS

Field Studies n n n Field studies are done in natural settings The aim is to understand what users do naturally and how technology impacts them. In product design field studies can be used to: - identify opportunities for new technology - determine design requirements - decide how best to introduce new technology - evaluate technology in use.

Field Studies n Two Approaches n n Outsider – observing and recording what happens as an outsider looking in Insider – participant in study that explores the details of what happens in a particular setting

Predictive Evaluation n Experts apply their knowledge of typical users, often guided by heuristics, to predict usability problems. n n Note: heuristics- design principles used in practice Another approach involves theoretically based models. A key feature of predictive evaluation is that users need not be present Relatively quick & inexpensive

Key Aspects of each Evaluation Paradigm n n n n Table 11. 1 – page 344 role of users who controls the process & relationship during evaluation location when is it most useful to evaluate type of data collected & how it is analyzed how findings are fed back to the design process philosophy that underlies these paradigms

Evaluation Techniques n n n Observing users Asking users their opinions Asking experts their opinions Testing users’ performance Modeling users’ task performance to predict the efficacy of a user interface

Observing Users n Techniques n n notes audio video interaction log

Asking users their opinions n Questions like: n n n what do you think about the product? does it do what you want? do you like it? does the aesthetic design appeal to you? did you encounter problems? would you use it again?

Asking experts their opinions n n n Use heuristics to step through tasks Typically use role-playing to identify problems It is inexpensive and quick to ask experts rather than perform laboratory and field evaluations

User Testing n n Recall Hutch. World example Usually conducted in a controlled environment Users perform well-defined tasks Data can be collected and statistically analyzed

Modeling users’ task performance n n n Model human-computer interaction to predict the efficiency and problems in the design This is successful for systems with limited functionality Table 11. 2 - page 347

DECIDE: framework Determine the goals the evaluation addresses. n Explore the specific questions to be n n n answered. Choose the evaluation paradigm and techniques to answer the questions. Identify the practical issues. Decide how to deal with the ethical issues. Evaluate, interpret and present the data.

Determining the Goals n n What are the goals of the evaluation? Who wants it and why? Goals influence the paradigm for the study. Some examples of goals: - - - Check that evaluators have understood user needs Check to ensure that the final interface is consistent. Investigate how technology affects working practices. Improve the usability of an existing product.

Explore the Questions n n All evaluations need goals & questions to guide them so time is not wasted on illdefined studies. For example, the goal of finding out why many customers prefer to purchase paper airline tickets rather than e-tickets can be broken down into sub-questions: - What are customers’ attitudes to these new tickets? - Are they concerned about security? - Is the interface for obtaining them poor?

Choose Evaluation Paradigm and Techniques n n n Evaluation Paradigms determine which type of techniques will be used. Trade-Offs Combinations of Techniques -Hutch. World

Identifying Practical Issues For example, how to: select users n stay on budget n staying on schedule n evaluators n select equipment n

Decide on Ethical Issues n n Consideration for peoples rights. Develop an informed consent form Participants have a right to: - know the goals of the study - what will happen to the findings - privacy of personal information - not to be quoted without their agreement - leave when they wish “do unto others only what you would not mind being done to you”

Evaluate, Interpret, and Present Data n n n Reliability Validity Biases Scope Ecological Validity

Pilot Studies n n n Pilot Study is a small trial run of the main study. Pilot studies are always useful for testing plans for an evaluation, before launching the main study Often evaluators run several pilot studies.