taskanalysis

toc = = =**Task Analysis**=

Task (tāsk) n. 1. A piece of work assigned or done as part of one's duties. 2. A difficult or tedious undertaking. 3. A function to be performed; an objective. ([|www.dictionary.com])

Overview
A task analysis is an important process in interactive design which entails breaking down all the possible steps in order to complete a specific task. Its purpose is to create a clear guide that will that will help one achieve their ultimate goal or goals.

Task analysis can be used for a variety of purposes. Wikipedia.org gives a broad definition of this conceptual tool stating that it is:

“The analysis or a breakdown of exactly how a [|task] is accomplished, such as what sub-tasks are required. This information can then be used for many purposes, such as improving the design of tools or procedures that aid in performing the task. These tools can be either physical implements or software.” (http://en.wikipedia.org/wiki/Task_analysis)

In regards to an interactive design system the text book //Designing Interactive Systems// offers a more precise definition. The book describes a that “A task Analysis is concerned with the performance of work by a work system” (Benyon, Turner & Turner, p.504).

To summarize a work system is created by the formation of people and technology in order to achieve a goal. The work that needs to be performed by this work system has to be clearly plotted inorder to reach success. First the goal must be defined and then the work system has to map out a list of task and actions that will result in reaching the deisred goal.

Types of Task Analysis
There are various types of task analyis however inorder to remain in tune with the text book I will focus on the three that are outlined within it.


 * 1) Hierarchical Task Analysis
 * 2) GOMS – Goals, Operators, Methods & Selection Rules
 * 3) Structural Knowledge

The hierarchical task analyis breaks down the process of achieving your goal into tasks, subtasks, and actions by order of importance and function.

For example if I wanted to wake up ar a specific time in the morning by using my alarm clock I would break it down in to following tasks and subtasks:

1 - Setting the time 1.2 - Programming the specific hour and minutes 2 - Choosing the time of Day 2.2 - Selecting either am or pm 3 - Turning the alarm on

GOMS is a popular form of cognitive task analyis. It’s purpose is to describe each task by breaking it down into the following categories:


 * 1) Goals – what is trying to be achieved.
 * 2) Operators – the actions used to perform the task.
 * 3) Methods – the sequences that will be used to achieve the goal.
 * 4) Selection Rules – the rules that enable a choice for different methods to be used.

It is important to note that the GOMS method is only applicable if the person is aware of exact what they are tyring to do. (Benyon, Turner & Turner, p.512).

Structural Knowledge works hand in hand with the notion that a task analysis is specifically about procedures.

Structural knowledge involves the concept of a mental model which is used to analyse tasks. S.JPayne breaks down a mental model into two specific parts:
 * 1) A Goal Space – the state of the domain the person is trying to achieve.
 * 2) Device Space –How the technology represents the goal space. (Payne, 2003).

By using Structural Knowledge as an approach to achieving a specfic goal you are able to create an analyis that understands the capability of the user trying to complete a task and how the technology will function inorder to enable the user to do so.

Conclusion
In order to achieve a goal in design interaction it is imperative to have a clear plan. By establing what the specific goal is and then selecting the appropriate form of task analysis you will in essence create a map that will lead you to your final destination of success.

It is also important to note that for the purpose of this essay I have chosen to follow interpretation of a task analysis that is used in the text book //Designing Interactive systems//.

The authors mention that a task analysis can be entrpreted by others to encompass various manners of technique however they disagree by stating the following “ We consider task analysis to be a specific view of interactive systems design that leads to specific techniques” (Benyon, Turner and Turner, p.503).