Usability & Human Factors

Usability & Human Factors
This is the final lecture on our topic Approaches to Design. Approaches to Design Lecture c This material(Comp15_Unit8c) was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1U24OC

Approaches to Design Learning Objectives
Explain the iterative design process (Lecture c) Describe principles of sound design to support usability (Lecture c) Describe how Nielsen’s heuristics and design principles apply to user interface design (Lecture c) The objectives of this lecture include developing a further understanding of the iterative design process. You should also be able to describe principles of sound design to support usability. In addition, there is an expectation regarding your ability to understand and describe how Nielsen’s heuristics and design principles apply to user interface design Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Design Principles to Support Usability (Dix et al, 2004)
Learnability Ease with which new users can achieve a) basic proficiency and then b) mastery Flexibility Flexible ways in which the user and system exchange information Robustness Level of support provided to user in determining successful achievement and assessment of goals The balance of this unit is focused on design principles. We first introduce a set of design principles to support usability drawing on the work of Dix and colleagues. They articulate 3 top-level principles which can be further decomposed. Learnability refers to the ease with which new users can achieve basic proficiency using a system and hopefully mastery at some point in time. Learnability is especially important in the context of health information technology because systems are often very complex and some time is needed to acquire basic proficiency. Flexibility refers to the ways in which the user and system exchange information, for example, through dialogue box exchanges. Robustness is the level of support provided to the user in determining whether they successfully achieved their goals. This includes being able to discern the state of the system and also being able to recover from errors. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Usability & Human Factors Approaches to Design Lecture c
Learnability Factors Predictability Support for the user to determine the effect of future action based on past Synthesizability User can understand effect of past operations on the current state of system Familiarity Extent to which a user’s knowledge and experience can be applied when interacting with a new system Learnability can be further decomposed into 5 principles. Predictability is a function of the support provided for the user to determine the effect of future action based on the past. Does the system offer a coherent experience or is there too much variability? Synthesizability refers to the extent to which users can understand effect of past operations on the current state of system. Familiarity is determined by the extent to which a user’s knowledge and experience can be applied when interacting with a new system. People usually choose a certain action based on the knowledge that they have gathered from various experiences throughout their lives. Generalizability is the support for users to learn new facets or components of the system. Consistency in this context is used to refer to commonalty in input-out behavior arising from similar situations or similar task objectives. For example, if you click on an object or select a menu, the system’s behavior will be largely predictable. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Learnability Factors Cont.
Generalizability Support for the user to extend knowledge within and across applications Consistency Likeness in input-out behavior arising from similar situations or similar task objectives Generalizability is the support for users to learn new facets or components of the system. Consistency in this context is used to refer to commonalty in input-out behavior arising from similar situations or similar task objectives. For example, if you click on an object or select a menu, the system’s behavior will be largely predictable. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Usability Principles and Design Heuristics (Nielsen, 1993)
Visibility of system status Match between system and the real world User control and freedom Consistency and standards Error prevention Error handling Recognition rather than recall Flexibility and efficiency of use Aesthetic and minimalist design Help and documentation In the unit on usability evaluation, we discussed Nielsen’s usability heuristics. We discuss them here to illustrate design decisions. These principles have had considerable influence on design and provide guideposts for design decisions. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

1. Visibility Keep users informed Make state transitions explicit Animate dynamic processes Visibility refers to the extent to which one can discern and comprehend the state of the system. The simplest example is if you are engaged in a five step or five screen processes. The screen should be clearly labeled as 3/5 (for example), noting that you are currently on screen and you have 2 more to go. System transitions can be confusing and they need to be made explicit to the user. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Be Obvious Where am I? What’s happening? What can I do? What do I need to know? Most users are not interested in “exploration” Usability is not co-extensive with deep hidden meanings in interactivity. Obviousness is an important attribute of system visibility. The questions suggest the need to keep the user focused on the task at hand and that the state of the system should be as transparent as possible. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Animate Slow Processes
Wait states can be very confusing to a user. Some transactions are going to take time and you want users to be able to monitor progress. This image is a glucose and blood pressure upload data screen from the IDEATel telemedicine study. The display indicates the process of patients’ uploading their values from their meters over the networks to a central server. It was a slow process and the blue bar represents the progress towards a complete upload. If the upload fails to progress, the patients would be clear that their data was not sent. This is valuable feedback. In this lecture, we will draw on a telemedicine study in which older adults with diabetes were given computers, glucose and blood pressure meters to better manage their diabetes. The participants were general low literacy and were relatively new to computing. Over the course of the study, many design changes were made to better accommodate user’s capabilities. In other words, we tried to make the system as intuitive and as accessible as possible for this population. Starren, J., Hripcsak, G., Sengupta, S., et al. (2002). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

2. Match System to World Avoid Jargon Speak the users' language Follow real-world conventions Present information in a natural and logical order The system should speak the users' language, with familiar words, phrases and concepts rather than system-oriented terms. It should follow real-world conventions, making information appear in a natural and logical order. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

3. User Control and Freedom
Clearly marked "emergency exit" Support undo, redo and “back” User configurable preference and interfaces Avoid fixed sequences One of the most frustrating experiences is if one of your actions cause you to unexpectedly leave the program. For example, as people transition to web-based applications, they need to remember that closing a window won’t only close a message, but will exit the program. Systems should support multiple undos and redos. There are many systems in which backward navigation is not permissible and this can be very frustrating. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

4. Consistency and Standards
Consistent placement Consistent action models Beware modal behaviors Follow platform conventions I am sure you have heard a lot about standards in learning informatics. Usability and design are no different. As discussed previously, consistency is very important in promoting system learnability. Some systems have multiple modes. For example, there are clinical information systems that will permit you to browse and search information. However, if you want to enter data, you need to switch to another mode. This can be very frustrating to the user. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

The Law of Least Astonishment
The system should never “surprise” the users. It should always behave in the “expected” manner The Law of Least Astonishment states that when two elements of an interface conflict, or are ambiguous, the behavior should be that which will least surprise the user. In particular, a developer should try to think of the behavior that will least surprise someone who uses the program, rather than that behavior that is natural from knowing the inner workings of the program. When it comes to using computers, surprises are generally not welcome. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

5. Error Prevention Make “bad things” hard to do Data checks before “submit” Identify errors early Confirm unrecoverable actions Avoid “dialog escape” To the extent possible, a system should endeavor to prevent users from making mistakes. They can be especially costly in the context of patient care. Some advice is to make “bad things” hard to do such as closing out a program without saving the data. In addition it is important to identify errors early so that the system can prompt a user before a submission. Some actions are irreversible and may inadvertently result in the loss of data. A system should warn the user about such actions. Lastly, people tend to think that escaping a dialog box immediately cancels an action when in fact, that is not always the case. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

6. Error Handling Help users recognize, diagnose, and recover from errors No codes Error messages should be expressed in plain language The very worst error messages are those that don't exist Precisely indicate the problem Suggest a solution Errors are inevitable and can be major irritants depending on how the system handles them. Systems should help users recognize, diagnose, and recover from errors. Error messages should be expressed in plain language without recourse to codes. The very worst error messages are those where no problem seems to exist. It is always best to suggest a solution or course of action rather than just stating the problem. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Some Favorite Error Messages
Abort? Retry? Fail? Ignore? -3162 Incorrect Magic Number does not like recipient. Permanent Compiler Error Panic Error: An unexpected error has occurred Error: The operation completed successfully Not too long ago, meaningless error messages were very common. That still happens, albeit much less frequently. My personal favorite on this list is “Error: The operation completed successfully”. Kaufman, D. (2010). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

7. Recognition, not Recall
Minimize users’ memory load Minimize hidden functions Make objects, actions, and options visible. Instructions visible or easily retrievable. The user should not have to remember information from one screen to another. Make sequential steps explicit Minimize command languages Proper Default Doses & Routes The importance of placing an emphasis on recognition is a hallmark principle of human factors, as well as human computer interaction. Accentuating cues in the interface serves to minimize users’ memory load. It is advisable to make objects, actions, and options visible in the graphical user interface. Cues in the interface should guide a user towards a series of steps and the user should not have to remember information from one screen to another. This is especially important in interfaces for Computer-based Provider Order Entry Systems (CPOE) that involve the management of a lot of information. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Icon If You Can Use icons to reinforce content Pictures recalled better than words Test your icons Avoid subtle distinctions Avoid “cute” metaphors Using icons instead of words or in addition to words can facilitate recognition. Like anything else in design, you want to test whether icons are readily discernible and not too cryptic for most users. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

8. Flexibility and Efficiency
Allow users to tailor frequent actions. Keyboard Shortcuts Macros / Scripting Programmable Interfaces Order Sets When systems are too rigid and inflexible, they tend to frustrate users—especially experienced ones. The following are some ways to promote flexibility and efficiency: allow users to customize frequent actions, employ Keyboard Shortcuts, and allow macros for repetitive tasks. Programmable interfaces afford users the ability to customize displays. There are a growing number of Web 2.0 tools that make this easier. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

9. Aesthetic and Minimalist Design
Screen content should relate to user’s goals Many users will not be able to separate relevant from irrelevant Design and Decoration should enhance visibility Remove item Test application If the application still works, leave it out The removal test More than any other company, Google with its Spartan-like search engine interface has embraced the minimalist design aesthetic. Screen content should relate to user’s goals. Many users will not be able to separate relevant from irrelevant and added clutter imposes a memory load on the user. Design and decoration should enhance visibility. The removal test: 1) Remove item, 2) Test application and 3) If the application still works, leave it out. Of course, this is not meant to be taken literally or to be applied in all cases. It’s the principle of pruning that which is not necessary that is operative here. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Color With Care Design in black and white Four or fewer colors
Avoid saturated colors Do not encode only in color Use color consistently Avoid color opposites Beware unintended color meaning Clarity of message and readability should be the order when it comes to issues of color selection. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Funday Of course some sites do it better than other ones. This website is a bit of an eye sore with a rather unfortunate color scheme. Although such sites are less common than they were ten years ago, you still come across sites that violate basic color scheme conventions. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

10. Help and Documentation
… until something breaks No one reads the manual Plan instructions for problem solving Many users accustomed to paper, not computer Step-wise, pictorial instructions Invaluable for remote support Test your documentation Sound help for users and documentation are generally undervalued. Keep in mind that no one reads the manual… until something breaks. So, plan instructions for problem solving. Step-wise, pictorial instructions are very useful. In addition, testing your documentation should be a part of usability evaluation. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Reducing System Barriers for Older Adults
IDEATel Informatics for Diabetes Education And Telemedicine Large-scale home-based telemedicine project for medically-underserved diabetic patients Older adults with limited computer literacy Usability testing revealed a range of user problems that impeded productive use As described earlier, I am now going to present a brief case study that focuses on iterative redesign of hardware and software designed for a remote telemedicine project for older adults with diabetes. The IDEATel project was a large-scale home-based telemedicine project for medically-underserved diabetic patients. Usability testing revealed a range of user problems that impeded productive use of the system. Consequently, the project team re-engineered the system in significant ways. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Changes to Design Simplify without reducing functionality! Go Big: large text and buttons Reduce memory load/minimize task complexity Improve contrast Enhance navigation Reduce burden on psychomotor skill Mouse-based system to touch screen Many changes to the design were made based on a better understanding of the study population which of older adults. Many of them were limited in their literacy and the vast majority of the population was new to computing. The interface was simplified over a series of iterations. The size of the text and interactive elements such as buttons grew in size to accommodate vision constraints. In addition, there was a significant hardware change as illustrated in the next slide. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Generations of Telemedicine Systems
The 2 images represent two generations of a telemedicine system. These are both workstations for patients to communicate with nurse case managers and to access various tools and educational materials to better manage their diabetes. The screen on the left is a first generation “old fashioned” system. The one on the right is a touchscreen system that was designed to be more intuitive and physically easier to use for elderly patients with low computer literacy. The first system was a conventional Windows, icon, and mouse-based computer. The mouse presented significant difficulties for many of the users who were older adults. The project embraced a touchscreen model that proved to be significantly easier to use for many of the participants. Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Diabetes Manager Gen 1a This is an illustration of the original patient interface. The small type and cluttered look presented problems for users. Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Diabetes Manager Gen 1b This second slide presents a modest iteration on the original design. Basically, everything is a little bigger with better spacing. Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Diabetes Manager Gen 2 To accommodate the new touchscreen system, additional changes were made to the system. The overall look and feel has been redesigned and a set of tools (e.g., to view blood pressure values over the period of a week or 2 weeks) were introduced that would make it easier for patients to view their data over time. This further improved the system and the patient’s experience. Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Pedometer Interface This is an example of an interactive screen. Participants were given a pedometer (shown in the lower right-hand corner of the screen), encouraged to walk daily and enter their steps into the computer using this display. The display was designed to resemble a calculator which is a familiar object. There was only one problem. The number of steps field was zero padded (zeros at the beginning) to resemble the actual device. As it turned out, this was very confusing for users. In general, the iterative changes in design resulted in a better computing experience for users. Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Approaches to Design Summary
Learnability factors are important and often overlooked Health information systems almost invariably necessitate a learning curve Adherence to basic design principles including Nielsen’s design heuristics can greatly improve a user’s experience Sound design does not eliminate the need for usability evaluation Today’s lesson focused on design and specifically principles to guide design. It should be noted that learnability factors are important and often overlooked. Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Approaches to Design References – Lecture c
. Dix, A., Finlay, J.E., Abowd, G.D., Beale, R. (2004). Human-Computer Interaction. 3rd ed. Essex, England: Prentice-Hall Nielsen, J. (1994). Heuristic evaluation. In J. Nielsen & R. L. Mack (Eds.), Usability Inspection methods (pp ). New York: Wiley. Mayhew, D. J. (1999). The usability engineering lifecycle. San Francisco, CA.: Morgan Kaufmann Publishers, Inc. Norma,n D.A. (1986). Cognitive engineering. In: Norman DA, Draper SW, editors. User centered system design: New perspectives on human-computer interaction. Hillsdale, NJ: Lawrence Erlbaum Associates; p Polson, P. G., Lewis, C., Rieman,J., & Wharton, C. (1992). Cognitive walkthroughs: A method for theory-based evaluation of user interfaces. International Journal of Man-Machine Studies, 36, Preece, J. Rogers, Y. & Sharp, H. (2007) Interaction Design: Beyond Human-Computer Interaction. 2nd Edition. New York, NY: John Wiley & Sons Ruland, C.M., Starren, J., Vatne, T.M. (2007). Participatory design with children in the development of a support system for patient-centered care in pediatric oncology. J Biomed Inform. Nov 13; Shea, S,. Starren, J,. Weinstock, R.S., Knudson, P.E., Teresi, J., and Holmes, D. et al. (2002). Columbia University’s Informatics for Diabetes Education and Telemedicine (IDEATel) Project: rationale and design, J Am Med Inform Assoc 9 (1), pp. 49–62. Starren, J,. Weinstock, R.S., Palmas, W., Izquierdo, R., Morin, P., and Kaufman, D.R. (2006). Diabetes. In: R. Wootton, S.L. Dimmick and J.C. Kvedar, Editors, Home telehealth, Connecting care within the community, pp. 171–183 No audio Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

Approaches to Design References – Lecture c
Images: Slide 9: Starren, J., Hripcsak, G., Sengupta, S., et. al. (2002). Columbia University's Informatics for Diabetes Education and Telemedicine (IDEATel) project: technical implementation. J Am Med Inform Assoc. 2002;9:25–36. Slide 16: Kaufman, D. (2010). Example of message errors. Department of Biomedical Informatics, Columbia University Medical Center, New York, NY. Slide 22: Retrieved August 10th, 2010 from Slide 26-30: Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., et. al. (2006). Re-designing a telehealth diabetes management program for a digital divide seniors population. Home, Healthcare, Management & Practice. 18: No audio Health IT Workforce Curriculum Version 3.0/Spring 2012 Usability & Human Factors Approaches to Design Lecture c

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