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Advanced Human Computer Interaction

Instructor: Dr. Nadeem Ahmad ChauhdryDual PhD (Politecnico di Torino, Italy & University of Potsdam, Germany)HOD, CS & IT Department,The University of LahoreDefence Road Campus, Lahore.Email: nadeem.ahmad.@cs.uol.edu.pkhttps://sites.google.com/site/pctresearchgroup/

User Centered Design

• Definitions of User Centered Design • Purpose of UCD• Four Important UCD Principles• UCD Methodology• User-Centered Design: A Case Study• UCD in System Design Life Cycle• UCD vs. Waterfall vs. Agile

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User Centered Design (UCD)

• User-centered design (UCD) is a type of user interface design and a process in which the needs, wants, and limitations of end users of a product are given extensive attention at each stage of the design process.

– Don Norman’s Definition (User centered system design; new perspectives on human-computer interaction: 1986)

• User-centered design (UCD) is an approach to design that grounds the process in information about the people who will use the product.

– Usability Professional Association

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User Centered Design (UCD)

• In UCD, all "development proceeds with the user as the center of focus”.

– Jeffrey Rubin (Handbook of Usability Testing: How to Plan, Design, and Conduct Effective Tests: 1984)

• Human centered design is an approach to interactive system development that focuses specifically on making systems usable. It is a multi-disciplinary activity.

– Human centered design processes for interactive systems, ISO 13407 (1999)

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Purpose of UCD

• The biggest cost benefit that UCD can provide is by more accurately defining requirements.

• Produce products that have a high degree of usability.

• The ultimate goal of UCD is to optimize a user's experience of a system, product, or process.More Information: http://www.michaelgaigg.com/blog/2009/03/05/benefits-principles-of-user-centered-design/

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Users Perspective

• Needs and Wants• Goals, Motivation and Triggers• Obstacles and Limitations• Tasks, activities and Behaviors• Geography and Language• Environment, Work, life and Experience

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Four Important UCD principles

• A clear understanding of user and task requirements

• Incorporating user feedback to refine requirements and design

• Active involvement of user to evaluate designs

• Integrating user centered design with other development activities

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UCD Methodology

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Typical UCD Methodology

• Analysis Phase• Meet with key stakeholders to set

vision• Include usability tasks in the project

plan• Assemble a multidisciplinary team to

ensure complete expertise• Develop usability goals and objectives• Conduct field studies• Look at competitive products• Create user profiles• Develop a task analysis• Document user scenarios• Document user performance

requirements

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• Design Phase• Begin to brainstorm design concepts

and metaphors• Develop screen flow and navigation

model• Do walkthroughs of design concepts• Begin design with paper and pencil• Create low-fidelity prototypes• Conduct usability testing on low-

fidelity prototypes• Create high-fidelity detailed design• Do usability testing again• Document standards and guidelines• Create a design specification

Typical UCD Methodology

• Implementation Phase• Do ongoing heuristic

evaluations• Work closely with delivery

team as design is implemented

• Conduct usability testing as soon as possible

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• Deployment Phase • Use surveys to get user

feedback• Conduct field studies to

get info about actual use• Check objectives using

usability testing

User-Centered Design: A Case Study on Its Application to the Tactical Tomahawk Weapons Control System (TTWCS)

• The TTWCS is a hardware and software system that is responsible for the initialization, planning, preparation, and launching of Tomahawk missiles.

• The broad goals given by the sponsor for the user interface were – To increase combat effectiveness – Reduce operator workload and – Improve situational awareness

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UCD Processes Integrated with APL Systems Engineering Loop

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• Further information: Case Study (http://www.jhuapl.edu/techdigest/TD/td3101/31_01_Rigsbee.pdf)• APL’s systems engineering process, known as the systems engineering “loop.”

http://www.jhuapl.edu/techdigest/TD/td2904/Seymour_Editorial.pdf

UCD Implementation: Case Study

• Requirements Elicitation– It is important that the interviewer understand the users’

lexicon, system, tools, and environment.– Identifying subject-matter experts (SMEs), or users who are

former or current operators of the system, is essential to develop background information on the roles relating to and supporting operations.

– SMEs are familiar with the shortcomings of existing systems and can identify valuable data on user preferences and desired design features.

– Notes were taken and refined into explicit requirements that eventually led to a high-level design concept document.

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The TTWCS Task Analysis Process

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TASK ANALYSIS: Top-Level Task Hierarchy

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Design Concepts and Artifacts

• Three primary design artifacts are produced during this phase– The first of which is the high-level design concept document,

which provides the basis and logic behind the user-interface design and guides the creation of an initial low-fidelity prototype.

– The high-level design concept document feeds into the HCI design specification document. The HCI design specification document provides an introduction and detailed screen layouts, colors, icons, and interaction methodologies.

– The third artifact is the user workflows.

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TTWCS Prototypes and Usability Testing

• Low-fidelity prototype was developed. This prototype began as a white board drawing a paper-based sketches finally into a presentation

• A medium-fidelity prototype was then created based on the feedback obtained from user reviews of the low-fidelity prototype.

• This prototype was more detailed and more dynamic than the low-fidelity prototype.

• The high-fidelity prototype was created next. This allowed operators to actually operate the system and complete various tasks.

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Results• Preliminary testing showed improvements in

– workload – situational awareness– the number of missiles launched on time – the number of errors and – the amount of help required to operate the new interface with

minimal training.

• Moreover, users and stakeholders help and feedback spread a positive message regarding the improved interface, which results in a boost in the users’ initial acceptance of the product.

• The design is currently in production and will be fielded in 2015.

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When should user experience design occur?

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UCD in System Design Life Cycle

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Understanding the User

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User Interface Design

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User Interface Design

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6 Basic Steps in UCD

1. Get to know the users2. Analyze user tasks and goals3. Establish usability requirements4. Prototype some design ideas5. Usability test the concepts6. Repeat as necessary

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Development process: UCD vs. Agile vs. Waterfall

Waterfall:-3-6 month + releases-Requirements definition

up front-Sequential process-Used heavily pre-Web-Delay testing to end

Agile:-”XP” Extreme

Programming-Reduce the cost of

change-30 day releases-Include user

involvement-Test as you go along

UCD:-User testing often-Iterative by

nature-Rapid (UI) design

prototyping-User test anytime

UCD vs. Waterfall vs. Agile

• Waterfall Model is best when you can not afford to learn from your previous mistakes.

• You do not design software for the space shuttle in an agile manner.

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Interfaces for Semi Literate Users

• I analyzed the effects and usability of providing online assistance to semi-literate users and compared different help modes.

• 250 semi-literate users in Republic of Rwanda participated in the experiment.

• 180 users were randomly divided into four different groups. Each group is further subdivided into three subcategories of basic, moderate and expert users.

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Categorization and literacy level of participants in each groupFormal Education

(Years)No. Of Participants

Male Female Total

Basic Users < = 3 12 3 15

Moderate Users > 3 & <= 6 12 3 15

Expert Users > 6 & <= 9 12 3 15

Methodology

• The experiments were carried out in two phases.

• In first phase, the Group A, applied for internship program using the original interface.

• 53% users were unable to perform the task. Only six out of fifteen from basic users category could answer all questions.

• Major usability barriers include language difficulty, required more detailed instructions and difficulty in understanding abbreviations.

• In 2nd phase three new interfaces were designed and tested on another group of semi literate users.

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Design process

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Results

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• All instructions were translated into their local language “Swahili”.

• Low literacy users are more benefited from online assistance with a twofold increase in their performance.

• The results are accepted with minor revisions in “International Journal of Human-Computer Interaction”.