Interaction design. The process of interaction design. Requirements. Data gathering. Interpretation and data analysis. Conceptual design.

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1 Interaction design The process of interaction design Requirements Data gathering Interpretation and data analysis Conceptual design Prototyping Physical design

2 Introduction We have looked at ways to gather information and gain an understanding of the work flow that will be incorporated into the design It is now necessary to understand how to organise this information and describe it in such a way that it is useful during the design page We often turn this data into requirement specification templates / documents to help us manage them

3 Requirements specification Requirements specification: documents / diagrams with information regarding name of the requirement, type, rationale, source, relationship with other requirements A guide to writing appropriate requirements specifications: (9,10,11)

4 Other ways: Work Models of Contextual Design CD = is a structured, well-defined user-centered design process that provides methods to collect data about users in the field, interpret and consolidate that data in a structured way The flow model captures communication and coordination between people to accomplish work. The cultural model captures culture and policy that constrain how work is done The sequence model shows the detailed steps performed to accomplish each task important to the work The physical model shows the physical environment as it supports or gets in the way of the work The artifact model shows the artifacts that are created and used in doing the work Holtzblatt, Karen and Beyer, Hugh R. (2013): Contextual Design. In: Soegaard, Mads and Dam, Rikke Friis (eds.). "The Encyclopedia of Human-Computer Interaction, 2nd Ed.". Aarhus, Denmark: The Interaction Design Foundation. Available online at

Interpretation & data analysis Contextual Design Other ways: Work Models of Contextual Design http://www.interaction-design.

2: The Flow Model captures communication and coordination between Figure 8.

It shows the different strategies people use, the intents or goals that their task steps are trying to accomplish, people to

Holtzblatt, Karengetting and Beyer, Hugh R. (2013): Contextual Design. In: communication patterns critical to doing the work.

Download or view: Full resolution into formal and informal roles and responsibilities.

5 Interpretation & data analysis Contextual Design Other ways: Work Models of Contextual Design Contextual Design Figure 8.2: The Flow Model captures communication and coordination between Figure 8.4: The Sequence Model shows the detailed steps performed to accomplish each task important to the work. It shows the different strategies people use, the intents or goals that their task steps are trying to accomplish, people to accomplish work. It reveals the formal and informal workgroups and and the problems in their way. Holtzblatt, Karengetting and Beyer, Hugh R. (2013): Contextual Design. In: communication patterns critical to doing the work. It shows how work is divided Copyright: See page copyright notice. Download or view: Full resolution into formal and informal roles and responsibilities. Soegaard, Mads and Dam, Rikke Friis (eds.). "The Encyclopedia of Copyright: See page copyright notice. Download or view: Full resolution Human-Computer Interaction, 2nd Ed.". Aarhus, Denmark: The Interaction Design Foundation. Available online at

Other ways: Personas Personas are detailed descriptions of imaginary people constructed out of wellunderstood, highly specified data about real people Personas do the job of creating a concrete,

6 Other ways: Personas Personas are detailed descriptions of imaginary people constructed out of wellunderstood, highly specified data about real people Personas do the job of creating a concrete, focused and stable definition of your audience John Prui*, Tamara Adlin (2006). The persona lifecycle: keeping people in mind throughout product design. Morgan Kaufmann Publishers, San Francisco, CA

7 Task analysis Task analysis: A way of documenting how people perform tasks A way of understanding goals and objectives Task analysis techniques used throughout the iterative process of design to gain a deep understanding of the requirements

8 Task analysis: scenarios Description of tasks Two often ways to describe tasks are Scenarios Use cases Scenarios A description in plain English of a typical task end-users may wish to accomplish with the proposed design It describes the basic goal, the conditions that exist at the beginning of the task, the activities in which the end-user or end-users will engage, and the outcomes of those activities

9 Task analysis: scenarios Two general types of scenarios: Task-based scenarios: state only what the user wants to do. Scenarios at this level do not include any information on how the user goes about completing the scenario Example: You are traveling to Dundee for your job next week and you want to check on the amount you can be reimbursed for meals and other expenses Elaborated scenarios: give the development team a deeper understanding of the users (example in next slide)

10 Task analysis: escenarios Example: Mr. and Mrs. Macomb are retired schoolteachers who are now in their 70's. Their Social Security checks are an important part of their income. They've just sold their big house and moved to a small apartment. They know that one of the many chores they need to do now is to tell the Social Security Administration that they have moved. They don't know where the nearest Social Security office is and it's getting harder for them to do a lot of walking or driving, so they would like to do this on the computer if it is easy and safe enough. However, they are somewhat nervous about doing a task like this by computer. They never used computers in their jobs; but their son, Steve, gave them a computer last year, set it up for them, and showed them how to use and how to go to Web sites. They have never been to the Social Security Administration's Web site, so they don't know how it is organized. Also, they are reluctant to give out personal information on Web sites, so they want to know how safe it is to tell the agency about their new address this way.

11 Task analysis: escenarios What things do we need to consider in the previous scenario? Easy and safe Lack of experience with similar sites Their son will probably give them a hand Privacy (personal information) Older people

12 Task analysis: scenario Exercise In groups, one member of the group will be the user, the rest, the researchers. You will talk to them about going about buying a book online Drawing on your conversation with the user Write down a task-based scenario describing the process of buying a book through an online book store Write down an elaborated scenario describing the process of buying a book through an online book store

13 Task analysis: use cases Use cases Represent a formal, structured approach to interpreting work flows and processes They are designed to describe a particular goal and explore the interaction between users and the system From the point of view of the user Two main components Actors: anything that has contact with or is affected by the system (humans and software, for instance) Use case: task or goal the actor is engaged in There are generally different paths Basic path: without any diversions Alternate path: paths to take depending on the situation

14 Task analysis: use cases Example Basic path Mr. and Mrs. Macomb enter the URL in the web browser The system asks for address Mr. and Mrs. Macomb trust the system and enter address The system shows confirmation message Alternate path Mr. and Mrs. Macomb do not trust the system They give a phone to Steve Steve introduces the address remotely for them

15 Task analysis: essential use cases Use Cases versus Essential Use Cases Why do we need to insert a card? And to press a key? Essential: focus on what, not on how Constantine, Larry L. i Lockwood, Luck A.D.. Sofware for Use. Addison Wesley, Reading, Massachusetts, Van Harmelen, Mark (editor). Object Modeling and User Interface Design. Designing Interactive Systems. Addison-Wesley, Boston, 2001.

16 Hierarchical Task Analysis HTA was originally designed to identify training needs It involves breaking a task into subtasks and then into subtasks and so on These are then grouped together as plans that specify how the tasks might be performed in an actual situation HTA focuses on the physical and observable actions that are performed, and includes looking at actions that are not related to software or an interaction device at all The starting point is a user goal This is then examined and the main tasks associated with achieving that goal are identified Were appropriate, these tasks are subdivided into subtasks

17 Hierarchical Task Analysis Consider the library catalog service and the task of borrowing a book This task can be decomposed into other tasks, such as accessing the library catalog, searching by name, title, subject going to the correct self and finally taking the book to the check-out counter This set of tasks and subtasks might be performed in a different order depending on how much is known about the book, and how familiar the user might be with the library and the book s likely location

18 Hierarchical Task Analysis 0. In order to borrow a book form the library 1. Go to the library 2. Find the required book 1. Access library catalog 2. Access the search screen 3. Enter search criteria 4. Identify required book 5. Note location 3. Go to correct shelf and retrieve book 4. Take book to check-out counter Plan 0: do If book is not on the shelf expected, do Plan 2: do If book not identified do

19 Hierarchical Task Analysis Plans control /show the flow Plan 0 assumes the book is on the correct shelf Plan 2 shows different ways of looking for a book Indentation shows the hierarchical relationship between tasks and subtasks Note how the numbering works for the tasks analysis: the number of the plan corresponds to the number of the step to which the plan relates

20 Hierarchical Task Analysis Borrow a book from the library 0 Go to the library Find the Retrieve book Plan 0: hacer Take Si el book libro to no está en la estantería, hacer required book 2 from shelf 3 counter 4 Access catalog Access search Enter search Identify Note location screen criteria required book Plan 0: do If book is not on the shelf expected, do Plan 2: do If book not identified do

21 Hierarchical Task Analysis An alternative expression of an HTA is a graphical boxand-line notation The subtasks are represented by named boxes with identifying numbers The hierarchical relationship between tasks is shown using a vertical line If a task is not decomposed any further then a thick horizontal line is drawn underneath the corresponding box Plans are also shown in this graphical form

22 Exercise Hierarchical Task Analysis Carry out an HTA (Hierarchical Task Analysis) for arranging a meeting in a shared calendar application 1 point for the tasks 1 point for the subtasks

23 GOMS GOMS (Goals, Operators, Methods and Selection rules) GOMS is a predictive model that gives the timing for a task as the sum of the timings for the individual operators used in the chosen method GOMS have been shown to be beneficial for assessing the relative merits of various design prototypes We have two designs, which one do we choose? A criterion could be according to GOMS (cognition, time) However, complex analysis can be very tedious, and tools are needed (e.g. CogTool)

24 Interpretation and data analysis GOMS (Goals, operators, methods and selection rules) Tasks are deconstructed as a set of goals and subgoals. Goals serve as memory points that enable the user to evaluate his or her progress. Operators Printing a document requires issuing a print command, which may involve clicking the printer icon, an operator. The lowest level in the model Methods Printing a document can be achieved in different ways (shortcut, icons ) Selection rules if the user is involved in intensive typing, shortcuts might be better; but if he is heavily mouse oriented, an icon might be the best option

25 Interpretation and data analysis GOMS (Goals, operators, methods and selection rules) Example Goal: Delete a piece of text from a Word document.

26 Interpretation and data analysis GOMS (Goals, operators, methods and selection rules) Example Method using the option from a menu Select text to be deleted The name of the option will be delete or erase The option should be in Edit Execute the option Delete the text

27 Interpretation and data analysis GOMS (Goals, operators, methods and selection rules) Example Method using delete key Mouse pointer before or after the text to delete Remember which key is the delete key Press key for deleting every letter Delete the text

28 Interpretation and data analysis GOMS (Goals, operators, methods and selection rules) Example Operators Left click Move the mouse pointer Select option from the menu Press delete key

29 Interpretation and data analysis GOMS (Goals, Operators, Methods and Selection rules) Example Selection rules A sentence: mouse + menu A word: delete key

30 Interaction design The process of interaction design Requirements Data gathering Interpretation and data analysis Conceptual design Prototyping Physical design

CS3205: Task Analysis and Techniques

CS3205: Task Analysis and Techniques CS3205: Task Analysis and Techniques Readings (same as before): 1) ID-Book Chapter Establishing Requirements, Ch. 10 (Ch. 9 in course ebook) 2) Chapter 2 from Task-Centered