Task-Centered system design
A variant of user-centered design, task-centered system design, is a technique that allows developers to design and evaluate interfaces based on users’ real-world tasks. As part of the design, this becomes a requirements analysis (requirements are the tasks to be performed). As part of the evaluation, evaluators can review prototypes and use tasks to create step-by-step scenarios of what users should do with the system. At each step of the walkthrough, you will be asked the following questions: Does the person have the knowledge to do it? If not, an error was found.
What is a task?
Tasks are characterized by how work is performed. Human actions that contribute to a useful goal in the system are tasks. Task analysis defines user performance, not computer performance.
Example: Payment Via Shopping App
TCD Principles
- Understanding user goals and needs: The design process begins by understanding the goals and needs of the users. This involves conducting research to gather information about the users, their tasks, and their environment.
- Identifying tasks: Once the goals and needs of users have been understood, the next step is to identify the tasks that they need to perform. This includes identifying the goals of each task, the steps required to complete it, and the information and resources that are needed.
- Designing for efficiency and effectiveness: The system should be designed to support the tasks identified in the previous step in the most efficient and effective way possible. This involves considering factors such as the layout of the interface, the organization of information, and the use of technology.
- Iterative design process: Task-centered system design is an iterative process, which means that the design is refined and improved through multiple cycles of testing and evaluation.
- User-centered design: User-centered design principles are emphasized in task-centered system design. This includes considering factors such as usability, accessibility, and user satisfaction when designing the system.
- Evaluation: Evaluation is an important part of task-centered system design. Testing and evaluating the system with users allows for feedback to be gathered and for changes to be made in order to improve the system.
TCD Phases
Task-centered system design (TCD) typically involves several phases:
- Analysis: This phase involves gathering information about the users, their tasks, and their environment. This includes conducting user research, such as interviews and surveys, as well as observing and analyzing the current system and workflows.
- Design: In this phase, the tasks identified in the analysis phase are used to design the system. This includes creating wireframes, mockups, and prototypes to visualize the sy andl as writing specifications and guidelines for development.
- Implementation: Once the design is complete, the system is implemented. This includes developing and building the system, as well as testing and evaluating it with users.
- Evaluation: In this phase, the system is evaluated with users to gather feedback and identify areas for improvement. This includes usability and well as gathering feedback through surveys and interviews.
- b: After the system is deployed, maintenance is performed to ensure that it continues to meet the needs of users. This includes addressing bugs, updating the system with new features, and making changes based on feedback from users.
It’s worth noting that TCD is an iterative process, and these phases may be repeated multiple times to ensure that the system is designed to meet the needs of users as effectively as possible.
Phase 1: How are the tasks identified?
Immerse yourself in a real person’s environment (exactly who, and exactly what)
- Observe people in their actual work context
- Interview people as they do their work
- Shadow a person over the course of his or her day
- Serve people’s requests
Designers should contact the real people who will be potential users of the system.
Designers spend time with potential users discussing how systems fit together and observing them.
They have to learn about the user’s tasks such as articulate concrete and detailed examples of tasks they perform or want to perform that the systems should and ask the user to verify. Figure Out Who’s Going to Use the System to do What
Figure Out Who’s Going to Use the System to do What
Figuring the details of tasks that users perform.
Here are some good task characteristics to consider when choosing:
- Information should be requested in the order in which the user is likely to receive it.
- It should be easy to correct data that is often entered incorrectly.
- Its hardware should fit in the space that users have available
- Understanding the users themselves
Knowing the user’s background helps designers answer questions such as what names to use for menu items.
There should be fewer quantifiable differences in users, such as their confidence, their interest in learning new systems, or their commitment to the design’s success, which can affect decisions such as how much feedback to provide or when to use keyboard commands instead of on-screen menus.
Phase 2: Requirements
Identified which user types will be addressed by the interface. Designs can rarely handle everyone, so designers at this stage should determine why certain users are included/excluded from tasks. Requirements should be listed in terms of how the tasks are typically tackled, as the design can rarely handle all the tasks.
Designs can rarely handle everyone and all tasks. Requirements are listed in terms of how they address tasks
- Absolutely must include
- Should include
- Could include
- Exclude
NOTE – Discussion includes why elements in these categories are classified.
Phase 3: Design as Scenarios
- Develop a design based on how well it fits the user and the specific task
- Use tasks to get specific about possible designs.
- Consider how design features work together to help a person accomplish real work
- Consider the real-world contexts of real users
- Reconsider how a design scenario handles each task
- What the user would do and see in each step of using the system to perform a task
- Develop designs that fit users and specific tasks
- Ground interfaces in reality
- Use tasks to learn about possible designs
- Real users consider the real-world situation of
- What should the user do
- See step-by-step when performing this task
Phase 4: Walk-through Evaluations
Good for debugging an interface.
The walkthrough is the fourth phase in task-centered design. A task-centered walkthrough is a low-cost way to evaluate and debug the interface of the system in the early stages of its development.
- The designer will develop designs around how well they fit users and specific tasks.
- Use tasks to specific about possible designs and consider how design features work together to help a person accomplish real work.
- The design should consider the real-world contexts of real users and reconsider how a design scenario handles each task.
Walkthroughs:
Evaluation of design through task-centered design walkthrough
- Selection of one of the task scenarios
- For each user step or action in the task :
- Carry out the action with the interface
- Ask :
- Would the user have done this activity in this way?
- Would the user’s expected knowledge to be sufficient
- Would the action be possible given the user’s situation?
- Is the feedback understandable and sufficient?
- If no :
- You’ve located a problem in the interface
- Once a problem is identified, assume it has been repaired
- Go to the next step in the task