1 / 18

Holistic Usability Measure (HUM)

Holistic Usability Measure (HUM). Juan E. Gilbert, Ph.D. IDEaS Professor & Chair Human-Centered Computing Division School of Computing Professor Automotive Engineering Clemson University juan@clemson.edu http://www.JuanGilbert.com/ http://www.HumanCenteredComputing.org/

lynnea
Download Presentation

Holistic Usability Measure (HUM)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Holistic Usability Measure (HUM) Juan E. Gilbert, Ph.D. IDEaS Professor & Chair Human-Centered Computing Division School of Computing Professor Automotive Engineering Clemson University juan@clemson.edu http://www.JuanGilbert.com/ http://www.HumanCenteredComputing.org/ http://www.clemson.edu/computing

  2. Usability! • “If you could build a system that resulted in world peace, but no one could use it ... it would be useless. Usability matters.” – Gilbert • However, “there has been no generally agreed-upon method of measuring usability, which makes it difficult to compare among different findings.” - Polkosky

  3. Holistic Usability • What is Holistic Usability? • Usability • Effectiveness, Efficiency, User Satisfaction • What really counts? • Effectiveness, Efficiency, or User Satisfaction? • Holistic Usability • A single measure of the overall usability

  4. System Usability Scale (SUS) Tullis and Albert’s Figure 6.8, based on Brooke 1996 10 statements to which users rate their level of agreement Half positive, half negative 5-pt scale of agreement Taken from http://jldrury.googlepages.com/8IssuesSelf-ReportedMetrics10-26-08.ppt

  5. System Usability Scale (SUS) • Each item's score contribution will range from 0 to 4. • For items 1,3,5,7,and 9 the score contribution is the scale position minus 1. • For items 2,4,6,8 and 10, the contribution is 5 minus the scale position. • Multiply the sum of the scores by 2.5 to obtain the overall SUS score.

  6. System Usability Scale (SUS) For items 1,3,5,7,and 9 the score contribution is the scale position minus 1. For items 2,4,6,8 and 10, the contribution is 5 minus the scale position. Multiply the sum of the scores by 2.5 to obtain the overall SUS score. Scores are on 100 point scale Taken from http://jldrury.googlepages.com/8IssuesSelf-ReportedMetrics10-26-08.ppt

  7. System Usability Scale (SUS) • SUS SCORE 0-60 GRADE = FSUS SCORE 60-70 GRADE = DSUS SCORE 70-80 GRADE = CSUS SCORE 80-90 GRADE = BSUS SCORE 90-100 GRADE = A

  8. System Usability Scale (SUS) • Nice for comparing systems • Short questionnaire • Easy to calculate • Doesn’t work across all systems

  9. Holistic Usability Measure

  10. Usability Goals • What is the goal of your interface/system? • Who decides the primary goal of the system? • Designer • Client • Manager

  11. Usability Goals • Did you build the right system/interface? • Who decides? • How do you know if your system is better than another that does the same tasks? • You must test it!

  12. Background • During requirement analysis, before design • Information design; what is to be built • What is the system/interface suppose to accomplish? • Who are the users? • Etc. • These are typical, but most people miss • Usability metrics • These are typically an afterthought • As a result, usability gets cut

  13. Background • Quantitative Metrics • Speech recognition accuracy • Task completion time • Subjective Metrics • User friendliness • Ease of use

  14. Background • Which metrics are most important? • It depends on your system/interface • Decide how you will test your system before you design it • Given several different metrics • How do you measure the overall effectiveness of the system/interface?

  15. Holistic Usability Measure • HUM • Assign each metric a weight (1 – 99%) based on its importance • Design and implement the system/interface • Evaluate it • Convert all metrics to a similar numerical scale

  16. Holistic Usability Measure • HUM = W1*Metric1 + W2*Metric2 + ... + Wn*Metric n • where W1 + W2 + ... + Wn = 1 • and 0 ≤ W1, W2, ..., Wn ≤ 1 • HUM yields a percentage measure rating the usability • according to the designer’s intent.

  17. Conclusions • HUM is a tool for testing • It reports usability with respect to the usability goals • Multiple ways to design same system. Which one is the best? • HUM is ideal for comparing more than one implementation of the same VUI • HUM is easy to use and it makes sense • Recall, “there has been no generally agreed-upon method of measuring usability, which makes it difficult to compare among different findings.” – Polkosky(SpeechTECH Magazine November/December 2005)

  18. Thank You Juan E. Gilbert, Ph.D. IDEaS Professor & Chair Human-Centered Computing Division School of Computing Professor Automotive Engineering Clemson University juan@clemson.edu http://www.JuanGilbert.com/ http://www.HumanCenteredComputing.org/ http://www.clemson.edu/computing

More Related