1. Usability & Human Factors
This lecture provides an overview of the process of design. We will introduce a couple of approaches known as Interaction and User-Centered Design. Then we will discuss Lifecycle Models, which provide an overview of the software engineering process. We will pay special attention to the Usability Engineering Lifecycle Model. Subsequently, we will explore the ways in which prototypes shape the design process. The process of Participatory Design which, engages users as designers, is illustrated in the context of an interesting case study about software for children with cancer.
Approaches to Design
Lecture a
This material (Comp15_Unit8a) 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

2. Approaches to Design Learning Objectives
Explain a user-centered design approach (Lecture a)
Define conceptual models (Lecture a)
Explain the iterative design process
Describe how requirements analysis influences design
The objectives of this lecture are for the student to be able to demonstrate an ability to explain a user-centered design and define conceptual models of design. Specifically, they should be able to explain an iterative design process and describe the ways in which requirements analysis shapes the design process. Therefore, by the end of this unit students will be able to:
1. Explain a user-centered design approach
2. Explain the iterative design process
3. Describe how requirements analysis influences design
4. Characterize the role of prototypes in design
5. Describe the principles of participatory design
6. Describe principles of sound design to support usability
7. Describe how Nielsen’s heuristics and design principles apply to user interface design
8. Explain the difference between low fidelity and high fidelity prototypes and when it would be appropriate to use one versus the other
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Usability & Human Factors Approaches to Design Lecture a

3. Usability & Human Factors Approaches to Design Lecture a
A plan or scheme conceived in mind and intended for subsequent execution
Tradeoffs balancing conflicting requirements
Generating alternatives
Use representations
Diagrams, prototypes
What do we mean by design? It refers to both a process of producing artifacts and a discipline devoted to the study of that process. The focus in this lecture is on software design; however, much of it would be relevant to other spheres of design as well. Whether we are talking about architectural or automotive design, they all engender a creative process in which something is produced to satisfy a population of users. They all must balance tradeoffs and sometimes, conflicting requirements. Design concepts are communicated via representations such as diagrams and prototype sketches.
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Usability & Human Factors Approaches to Design Lecture a

4. Usability & Human Factors Approaches to Design Lecture a
Interaction Design
Focus on Users
Specific Targets
Usability
Experience
Iteration
Key Question: How to optimize the users’ interactions with a system so they support and extend users’ activities in effective, useful and usable ways
Interaction Design is a broad-based approach that places a premium on the role of the user in design. The focus is on enhanced usability and on the user experience. The approach is committed to an iterative approach leading to refinements. The key question is how to optimize the users’ interactions with a system so as to support and extend users’ activities in effective, useful and usable ways.
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5. Why All the Fuss About Design?
Documented usability problems in healthcare and their consequences
Clinical information systems present problems in implementation & beyond
Many systems do not adequately address customer specifications
Fixing a problem in development phase costs 10 times more than in design phase
Really, why all the fuss about design? Why is it a process we need to worry about? We would all agree that design choices are consequential in the arena of health. Many of you have learned about the numerous usability problems and the ways in which they can compromise patient safety. We also understand the immense challenges involved in implementing clinical information systems. In addition, there is evidence to suggest that fixing a problem in the development phase may cost 10 times more than it does in design phases. No one truly disputes that sound design can make a significant difference.
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6. Usability Engineering
Requirements Analysis
Conceptual Mockup
Screen Design Standards
Prototype
Detailed UI Design
Install
Feedback
Enhancement
Usability Engineering is a field or an approach oriented towards accentuating the user experience in the design process. How can we make the system more intuitive and easy to use? The following are the steps involved in the process from a Usability Engineering perspective. We will particularly devote some time to discussing requirements analysis and conceptual mockups. Detailed UI design, install, feedback and enhancement reflect the iterative approach to refining the interface and the system to better meet users’ needs.
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7. A User-Centered Approach
Cognitive, behavioral & attitudinal characteristics
Nature of tasks performed
Early focus on users and task
Study of users
Empirical measurement
Design and development are responsive to user problems
Cyclical process
Iterative Design
One of the central themes of interaction design and usability engineering is the importance of a User-Centered Approach. Indeed, it is a central focus of this unit on design. There are three core commitments to this approach, which includes a focus on users and tasks very early in the design and conceptualization process. The approach is also predicated on empirical measurement of users both prior to having used the system and while using the system. The measures and observations of performance feed into an iterative design process.
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Usability & Human Factors Approaches to Design Lecture a

8. Focus on Users and Tasks
Users’ tasks and goals drive development
Focus on user behavior and context of use
System designed to support them
Capture characteristics of users (capabilities & constraints)
Users are involved from the inception through cycles of iterative development
All design decisions taken within context of users, their work and environment
Let’s expand on the idea of focusing on users and tasks. In a User-Centered Approach, they drive the development process. The system in question is designed to support humans in facilitating performance on a task like determining a patient’s prior health status, for example, by retrieving electronic documents in a clinical information system. The system needs to be shaped by an understanding of the capabilities as well as the limitations of the user (e.g., attention and memory constraints). The User-Centered Approach emphasizes that users are involved from the inception through cycles of iterative development. Furthermore, all design decisions are influenced by user considerations.
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9. Usability & Human Factors Approaches to Design Lecture a
Design Process
This diagram illustrates an iterative design process. First, we begin with a needs/requirements analysis leading to the development of design alternatives. Then, we create prototypes, which take shape as actual products. These are implemented in practice and subject to rounds of evaluation.
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Usability & Human Factors Approaches to Design Lecture a

10. Design Thought Exercise
Imagine you organize your books, CDs and DVDs into a system/database that provides easy access to all information that you need
Imagine doing it for a friend or your father who is just learning to use a computer
Kaufman, D. (2012).
Here’s a little design thought experiment. The goal is to wrap your head around some of the issues connected to the design process. Imagine you were going to organize all of your books, CDs and DVDs into a system or database that provides easy access to all the information you need. This is a task that seems daunting for some of us. Now, imagine you were going to put together a system for someone else and perhaps that person was less computer savvy than you.
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Usability & Human Factors Approaches to Design Lecture a

11. Think About the Space Problem
What are we trying to accomplish?
Organizing content
Ease of access, support queries
Supporting tasks
Users with different skill levels
(desktop, laptop, iPhone)
Support different displays
Define conceptual model
Think through the process of how you would provide functions for organizing the content, retrieving information and responding to queries such as how many Woody Allen movies do you have in your DVD collection? How might you design a display for your iPhone or iPad? The goal is not to think about software development or even what an interface would look like; rather, it is the conceptual model or abstract structure that would support such a task.
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12. Usability & Human Factors Approaches to Design Lecture a
Conceptual Model
Structure outlining the concepts and relations that form the product—not the user interface
Abstraction outlines what people can do with a product and concepts needed to understand how to interact with it
Metaphors used to convey a product
Concepts including the task domain objects, their attributes and operations that can be performed
Mappings between concepts and user experience
What do we mean by a conceptual model? It refers to an abstraction that outlines what people can do with a product and concepts needed to understand how to interact with it. It provides a structure outlining the concepts and relations that form the product—not the user interface. These concepts include the task domain objects, their attributes and operations that can be performed. For example, the task domain may be personal health, the objects are the data that inform you about your health and these particular findings or personal data have attributes. For example, you may have last had a checkup 13 months ago. The conceptual model also defines mappings between concepts and user experience.
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13. Usability & Human Factors Approaches to Design Lecture a
Visicalc
Why are we showing you a display of a program that was used many years ago? VisiCalc was the first spreadsheet program available for personal computers. It was something of a revolutionary product and according to some insiders, it turned the personal computer, initially a toy for electronic hobbyists and other geeks, into a serious business machine. What makes this of interest to us is that it was predicated on a robust conceptual model. Incidentally, the program was not a great commercial success, but it laid the groundwork for other spreadsheet programs, most notably, Microsoft Excel.
Wikimedia Commons GNU General Public License
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14. Visicalc Conceptual Model
First spreadsheet-a robust conceptual model (CM) that endures
Create a piece of software analogous to a ledger sheet—already familiar to users
Make it interactive allowing user to input and change data in any of the cells
Perform a range of calculations in response to user input
Target a range of users
Key goals of CM:
The core elements of the conceptual model (CM) were to produce an intuitive, easy to use and familiar product that everyone can relate to. The spreadsheet was modeled on a ledger sheet, which is an artifact that is familiar to most people running a business as well as accountants and so forth. It was designed as an interactive tool allowing users to input and change data in any of the cells. The program performed a range of calculations in response to user input. It was designed to be used by anyone needing to do calculations and therefore targeted a range of users. Thus far, we have said nothing about the program’s architecture or even its interface. The CM is used to derive a set of abstract goals and these goals may be achieved many different ways.
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Usability & Human Factors Approaches to Design Lecture a

15. Represents activities involved in the design process
Lifecycle Models
Represents activities involved in the design process
Prototypical Models
Waterfall
Spiral
RAD
Star
Usability Engineering
Lifecycle Models impose a structure on the software development process. There are several models for such processes, each describing approaches to a variety of tasks or activities that take place during the process. Lifecycle Models are important topics in software engineering. We will be selective in our presentation, given that our focus is on human computer interaction. Specifically, we will talk about the Waterfall, Star and Usability Engineering models. We will explore the usability engineering lifecycle in greater detail than the others.
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Usability & Human Factors Approaches to Design Lecture a

16. Waterfall Lifecycle Model
Requirements Analysis
Design
Code
Test
Maintain
This diagram illustrates the 5-step process in the Waterfall Lifecycle Model beginning with a requirements analysis onward to the different phases of the development process including design, code, test and maintain.
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17. Usability & Human Factors Approaches to Design Lecture a
Waterfall Model
The original model for software engineering
Linear model with clearly delineated tasks
Problems
No central role for users/no iteration and limited feedback
Too rigid—not responsive to requirement changes
Inconsistent with designers inherently nonlinear work practices
The Waterfall Model is the original model for software engineering and was immensely influential. It is a linear model with tasks that follow each other in a clearly defined sequence. There are known problems with the model including the fact that 1) users don’t play a central role, 2) it doesn’t really allow for iterative design and 3) it isn’t responsive to changes in requirements that ensue during the development process. The model was also found to be inconsistent with designers’ inherently nonlinear work practices.
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18. Usability & Human Factors Approaches to Design Lecture a
Star Lifecycle Model
Implement
Prototype
Evaluate
Requirements
Concept
Task Analysis
One can visually see the ways in which the star model differs from the waterfall model. It is a model designed to afford considerable flexibility and support creativity in the design process.
Preece, J., Rogers, Y., & Sharp, H. (2007).
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19. Star Lifecycle Model (cont.)
Inherently nonlinear—does not specify ordering of activities
Accentuates bottom-up, free thinking and creative practices of designer
Evaluation is viewed as integral to all stages and continuous
Problem: Too much flexibility, lack of systematic coordination and process is underspecified
It does not specify any ordering of activities. The model accentuates freethinking that is believed to be more typical of the practices of designers. Evaluation is viewed as integral to all stages and continuous. The problem with the Star Model is that it does not specify a structured process. Therefore, it affords TOO MUCH flexibility and makes systematic coordination among developers to be rather difficult.
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Usability & Human Factors Approaches to Design Lecture a

20. The Usability Engineering Life Cycle
User Profile
Task Analysis
Platform Capabilities/
Constraints
General Design Principles
Usability Goals
Style Guide
Work Re-engineering
Conceptual Model (CM) Design
CM Mockups
Iterative CM Evaluation
Screen Design Standards (SDS)
SDS Prototyping
Iterative SDS Evaluation
Detailed User Interface Design (DUID)
Iterative DUID Evaluation
Level 1
Level 2
Level 3
Met Usability Goals?
Yes No
Eliminated Major Flaws?
Start Application Design/Development
Model/Implementation Model
Start Application Architecture
Requirements Analysis A
Design/Testing/Development
Functionality Addressed?
The Usability Engineering Life Cycle
This model was developed by Deborah Mayhew in 1999, though others such as Jakob Nielsen also played a role in its gestation. The Usability Engineering Lifecycle Model is one of much greater complexity and detail. As the title suggests, usability goals are central to all phases of the design process. The details of the model are beyond the scope of this class. However, the diagram nicely illustrates the importance of requirements analysis and the multistep approach which is cyclical or iterative in nature.
Mayhew, J.D. (1999).
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21. Usability Engineering Lifecycle (UEL)
Developed by Mayhew (1999) with the goal of thoroughly integrating usability considerations into all phases of design
Core aspects/superordinate phases:
Requirements analysis
Design/testing/development
Decomposed into levels & detailed subprocesses
The model consists of 2 phases: 1) a requirements analysis phase and 2) a design/testing and development phase. In addition, each of these can be decomposed into sub processes and the second phase can also be broken down into levels of design from early stages to the latter stages of development.
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Usability & Human Factors Approaches to Design Lecture a

22. UEL Requirements Analysis
User(s) Profile
specific user/population characteristics related to interface design
Contextual task analysis
users’ current tasks, workflows and conceptual frameworks
Usability goal setting
Qualitative and quantitative goals reflecting minical acceptable performance
Platform capabilities and constraints
General design guidelines
We have previously discussed requirements analysis earlier in this lecture and in prior units. For the present purposes, it is important to understand the emphasis on profiling the user characteristics and accentuating the contextual elements of task analysis. This refers to the need to understand tasks in the context of workflow, for example, in a particular setting situated or in a given organization. Usability goal setting is a novel aspect of Lifecycle Models. The design process is oriented towards meeting specific qualitative goals such as user satisfaction and quantitative ones such as speed and accuracy.
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23. UEL Design Phase: Level 1 Design
Work Re-engineering
Based on requirements analysis
Abstract organization and workflow
Conceptual Model (CM) Design/Mockups
Navigational pathways and major displays are identified
Expressed as paper and pencil or prototype
Iterative CM Evaluation
Mockup is evaluated as if it were a real interface
This phase is largely devoted to translating requirements into conceptual models. Navigational pathways and major displays are identified and expressed as prototypes. The models are then subjected to evaluation and there is an iterative process.
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24. UEL Design Phase: Levels 2 and 3
Screen Design Standards/ Prototyping & Evaluation
Standards, conventions and themes applied to all screens
Formal usability testing evaluation
Standardized and validated as a style guide
Detailed User Interface Design
Based on refined conceptual model and screen design standards
Iterative Detailed User Interface Design Evaluation
Expanded usability evaluation to unassessed subsets of functionality and categories of users
Each upward level reflects a progression in the crystallization of standards, conventions and themes leading to the development of a style guide that is applied to all screens. Level 3 moves towards a more concrete level of detail in the development of software. In addition, user interface design evaluation takes on an increasing prominent role. The model also specifies a need to ask whether usability goals gave been met.
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Usability & Human Factors Approaches to Design Lecture a

25. Approaches to Design Summary – Lecture a
Focus on design as a plan or scheme conceived in mind and intended for subsequent execution
Tradeoffs
Conceptual model outlines what people can do with a product and ways to understand how to interact with it
Design Lifecycles
Up next: focus on requirements, prototypes and participatory design
In summary, our focus has been on the process of design as a scheme leading to a product designed for particular users and tasks. We discussed the role of conceptual models in articulating the shape of design and considered three design lifecycle models. In the next lecture, we will discuss the role of requirements in influencing the design process, examine the development of prototypes and introduce the participatory design process.
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26. Approaches to Design References – Lecture a
Kaufman, D.R., Pevzner, J, Hilliman, C., Weinstock, R.S., Teresi, J. Shea, S. & Starren, J. (2006). Re-designing a telehealth diabetes management program for a digital divide seniors population. Home, Healthcare, Management & Practice. 18:
Hilliman, C.A., Cimino, J.J., Lai, A.M., Kaufman, D.R., Starren, J.B., Shea, S. (2009). The effects of redesigning the IDEATel architecture on glucose uploads. Telemed J E Health. Apr;15(3):
Images
Slide 10: Kaufman, D. (2012). Design through exercise. Personal picture- Department of Biomedical Informatics, Columbia University Medical Center.
Slide 13: Retrieve d August 20th, 2010 from Wikimedia Commons GNU General Public License
Slide 18: Preece, J., Rogers, Y., & Sharp, H. (2007). Interaction Design: Beyond Human-Computer Interaction (2nd ed.). West Sussex, England: Wiley.
Slide 20: Mayhew, J.D. (1999). The Usability Engineering Lifecycle: A Practitioner’s Guide to User Interface Design. Morgan Kaufmann Publishers Inc., California.
No audio
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