Task Descriptions (Hierarchical Task Analysis)

A structured, objective approach to describing users’ performance of tasks, hierarchical task analysis originated in human factors. In its most basic form, a hierarchical task analysis provides an understanding of the tasks users need to perform to achieve certain goals. You can break down these tasks into multiple levels of sub tasks  In user experience, you can use hierarchical task analysis to describe the interactions between a user and a software system. When designing a new system, hierarchical task analysis lets you explore various possible approaches to completing the same task. When analyzing an existing system, it can help you to optimize particular interactions.

Applying Hierarchical Task Analysis to User Experience

Hierarchical task analysis requires a detailed understanding of users’ tasks. You can achieve this understanding by,

1. Identifying users’ primary goals
2. Detailing the steps users must perform to accomplish their goals
3. Optimizing these procedures

Example Hierarchical Task Analysis for ordering a book:

0.In order to borrow a book from the library 

1. go to the library 

2. find the required book

2.1 access library catalogue

2.2 access the search screen

2.3 enter search criteria

2.4 identify required book 

2.5 note location

3. go to correct shelf and retrieve book

4. take book to checkout counter

HTA Diagram

Task Descriptions (Use Cases)

What is a UML Use Case Diagram (UCD), and when to use it?

UML Use Case Diagrams can be used to describe the functionality of a system in a horizontal way. That is, rather than merely representing the details of individual features of your system, UCDs can be used to show all of its available functionality. It is important to note, though, that UCDs are fundamentally different from sequence diagrams or flow charts because they do not make any attempt to represent the order or number of times that the systems actions and sub-actions should be executed.

UCDs have only 4 major elements: 

1. The actors that the system you are describing interacts with, 
2. The system itself, the use cases,
3. Services, that the system knows how to perform,
4. The lines that represent relationships between these elements. 

Task Descriptions (Scenarios)

A scenario is a description of a person’s interaction with a system. Scenarios help focus design efforts on the user’s requirements, which are distinct from technical or business requirements. Scenarios may be related to ‘use cases’, which describe interactions at a technical level. Unlike use cases, however, scenarios can be understood by people who do not have any technical background. They are therefore suitable for use during participatory design activities.

When are scenarios appropriate?

Scenarios are appropriate whenever you need to describe a system interaction from the user’s perspective.

They are particularly useful when you need to remove focus from the technology in order to open up design possibilities, or when you need to ensure that technical or budgetary constraints do not override usability constraints without due consideration.

Scenarios can help confine complexity to the technology layer (where it belongs), and prevent it from becoming manifest within the user interface.

Task Analysis

Task analysis analyses what a user is required to do in terms of actions and/or cognitive processes to achieve a task. A detailed task analysis can be conducted to understand the current system and the information flows within it. These information flows are important to the maintenance of the existing system and must be incorporated or substituted in any new system. Task analysis makes it possible to design and allocate tasks appropriately within the new system. The functions to be included within the system and the user interface can then be accurately specified.

Key Concepts

• A user goal    = a state an end-user wishes to achieve 
• A user task    = a user activity required to bring about a goal
• A user action = physical activity (part of a task) with or without a computer

Mobile HCI 2012 Paper Review Presentation

Data Gathering

Data Collection is an important aspect of any type of research study. Inaccurate data collection can impact the results of a study and ultimately lead to invalid results.

Data collection methods for impact evaluation vary along a continuum. At the one end of this continuum are quantitative methods and at the other end of the continuum are Qualitative methods for data collection

Quantitative and Qualitative Data collection methods

The Quantitative data collection methods, rely on random sampling and structured data collection instruments that fit diverse experiences into predetermined response categories. They produce results that are easy to summarize, compare, and generalize.

Envisioning Users (User Profiles)

What is a User Profile?

A user profile is a realistic (but likely fictional) example of a target audience member. The profile commonly takes the form of a one page piece that lists the user’s name, occupation, education, demographic characteristics, computer/web experience, and site goals or likely tasks. A stock photography picture is usually used to give a face to the profile.

For a example: