COMP 3020: Human-Computer Interaction I Scenarios and Task Decompositions PDF

COMP 3020: Human-Computer Interaction I Scenarios and Task Decompositions Andrea Bunt, with acknowledgements to Anthony Tang, James Young, Pourang Irani, Julie Kientz, Michael Terry, Saul Greenberg, Christopher Collins, Karyn Moffatt  Task-Centred Design Another c...

COMP 3020: Human-Computer Interaction I Scenarios and Task Decompositions Andrea Bunt, with acknowledgements to Anthony Tang, James Young, Pourang Irani, Julie Kientz, Michael Terry, Saul Greenberg, Christopher Collins, Karyn Moffatt  Task-Centred Design Another common form of Try and Learn Uses insights from user-centred design process to generate task descriptions that can guide design 2 Task-Centred Design Use structured and organized descriptions of existing or envisioned tasks of a system Scenarios and Tasks informal narrative stories, simple, ‘natural’, personal, not generalizable to other tasks but representational Task Decomposition Structured way to formalize and break a task down into the important steps and components The focus is on what people want to do, not the technology 3  Scenarios Scenarios are “informal narrative descriptions” Provide a rich, detailed and personalized description of how a task is accomplished Not intended to capture a full set of requirements Offer a personalized, detailed account from only one perspective The focus is how people are accomplishing tasks, not the technology 4 Why scenarios and tasks are awesome Reduces hand-waving: forced to be concrete and specific about typical uses easily accessible, understandable by users, interaction designers, and developers 5  Example Scenario A scenario for a shared travel organizer: “The Thomson family enjoy outdoor activity holidays and want to try their hand at sailing this year. There are four members of the family: Sky who is 10 years old, Ryder who is 15 years old, Claire who is 35, and Will who is 40. While out on a shopping trip they call by at the travel agents in their local town to start exploring the possibilities... The travel organizer is located in a quiet corner of the agents’ office, where there are comfortable seats and play things for young children. They all gather around the organizer and enter their initial set of requirements—a sailing holiday for four novices. The organizer’s screen is designed so that all members of the family can interact easily and comfortably with it. The system’s initial suggestion is that they should consider a flotilla holiday, where several novice crews go sailing together and provide mutual support for first-time sailors…” Important details described: used by a diverse group describes context of use indicates sequence of task steps DOES NOT TALK ABOUT TECHNOLOGY 6  Scenario emerging from data A scenario generated by potential user of a library catalog service “Say I want to find a book by George Jeffries. I don’t remember the title but I know it was published before 1995. I go to the catalog and enter my user password. I don’t understand why I have to do this, since I can’t get into the library using the catalog without passing through the security gates. However, once my password has been confirmed, I am given a choice of searching by author or by date, but not the combination of author and date. I tend to choose the author option because the date search usually identifies too many entries. After about 30 seconds the catalog returns saying that there are no entries for George Jeffries and showing me the list of entries closest to the one I’ve sought. When I see the list, I realize that in fact I got the author’s first name wrong and it’s Gregory, not George. I choose the entry I want and the system displays the location to tell me where to find the book.” Note: importance of getting author’s name right annoyance of having to put in password limited search options importance of showing list of similar entries when an exact match isn’t clear 7  Creating a Scenario Should encompass the range of activities that follow the line of thought built from the conceptual model focus on what the person wants to do, not how they do it not focused on technology no assumptions about the interface is very specific (is this a contradiction?) describes a complete job 8  What is wrong with this scenario? A student is trying to register for a course in the university’s online system. First they go to the website and login. After clicking the submit button, they select the panel for courses. Then they browse the course list and click on computer science, and after the current term’s offerings come up, they select the course they want. 9  Improved A student is trying to register for a course in the university’s online system. First they login to the system, and following, navigate to the website section that enables them to register in courses. Then they navigate or narrow their registration to computer science courses so that they can browse the list of courses. Following, they register in the course they are interested in. But still missing richness 10 Task-Centred Design Use structured and organized descriptions of existing or envisioned tasks of a system Scenarios informal narrative stories, simple, ‘natural’, personal, not generalizable to other tasks but representational Task Decomposition Structured way to formalize and break a task down into the important steps and components The focus is on what people want to do, not the technology 11  Hierarchical Task Analysis (HTA): Example Cleaning a house decomposed into subtasks 0. To vacuum the house 1. get the vacuum cleaner out 2. put on the appropriate attachment 3. vacuum the rooms 3.1 vacuum the hall 3.2 vacuum the living rooms 3.3 vacuum the bedrooms 4. empty the dust bag 5. put the vacuum cleaner and attachments away 12  Adding Plans Plans specify alternatives for how a task might unfold Cleaning a house decomposed into subtasks 0. To vacuum the house 1. get the vacuum cleaner out 2. put on the appropriate attachment 3. vacuum the rooms 3.1 vacuum the hall 3.2 vacuum the living rooms 3.3 vacuum the bedrooms 4. empty the dust bag 5. put the vacuum cleaner and attachments away Plan 0: do 1-2-3-5 in that order when the dust bag gets full do 4 Plan 3: do any of 3.1, 3.2 or 3.3 in any order depending on which rooms need cleaning 13 Many different HTAs possible E.g., If we know that we only ever notice the bag is full when we are actively using the machine, we would put this subtask within subtask 3 ‘clean the rooms’ If we wanted to be more precise about when the rooms are cleaned: Plan 3: do 3.1 every day 3.2 once a week when visitors are due Restructuring and finding appropriate meaning is part of HTA 14 Scenario -> Hierarchical Task Analysis Scenario 1: George, a regular library visitor approaches Mary at the reference desk and asks if they have the Frankenstein comedy DVD. She asks if he means "Young Frankenstein" by Mel Brooks, and he say yes. She then directs him to the shelf where the DVD is expected to be. George retrieves his library card and brings it to the front desk. Mary checks out the DVD, but reminds George that he has $3.75 in unpaid fees. George says that he will pay the fees at a later date. Mary asks whether George would like a email or printed receipt. George says that email is fine and leaves with the DVD. Discussion: This task description contains many typical activities, which deal with vague requests about titles, the location of items in the library, as well as reminders about late fees. Most of these tasks are frequently done, and important. 15 Scenario -> Hierarchical Task Analysis Locating a DVD in a library 0. Locate a DVD: 1. Go to the front desk 2. Find the location of DVD on the shelves 2.1 Access the search screen 2.2 Enter the search criteria 2.3 Identify the DVD requested 2.4 Record the location of the movie 3. Go to correct shelf to get the DVD 4. Take the DVD to the front desk Plan 0: do 3-4. If DVD isn’t on stacks do 1-2-3-4. Plan 2: do 2.1-2.2-2.3-2.4. 16  Scenario -> Hierarchical Task Analysis Signing out a DVD 0. Sign out a DVD 1. Enter library care information 2. Decide to sign out video 2.1 Check member’s overdue fee status 2.2 Inform member of fees 2.3 Accept to give out DVD 2.4 Decline signing out DVD 3. Get video information 4. Sign out video 5. Give receipt 5.1 Give paper receipt 5.2 Email receipt Plan 0: do 1-2-3-4. If member not on file do 1-2-[Add member]-3-4 Plan 2: do 2.1-2.2-2.3. If member has a large number of late videos 2.1-2.2- 2.4. Plan 5: If member wants paper do 5.1, otherwise do 5.2. 17  Hierarchical Task Graph (HTG) for “Locate DVD” Locate DVD 0 Plan 0: do 3-4. If DVD isn’t on shelves do 1-2-3-4. Go to front Find DVD Go to stack Take DVD to desk on shelfs to get DVD front desk 4 1 2 3 Plan 2: do 2.1-2.2-2.3-2.4. Access Enter Identify Record search search requested location screen 2.1 criteria DVD 2.3 2.4 2.2 18  Validating the tasks and scenarios Get a reality check of your task list by asking end users and/or client representatives to review your tasks Were any details left out of the original task description? Get corrections Clarifications Suggestions Re-write the task descriptions 19  Task analysis –working through system ideas Use your task to evaluate a system does the system support the action flow and cognitive model? Also evaluate your task does the task limit what technologies it can be used on? Can be used in prototyping, evaluation, etc. 20  Combine with personas Use the character profiles (aka personas) (from prior class) Does the person fit the task and scenario? Why or why not? 21  Messages Scenarios and task descriptions are a great way to solidify and formalize your understanding of your users’ needs and use cases A more tractable, succinct representation of all the data from investigation You can use tasks and scenarios as tests against your ideas, prototypes, and systems 22