# Task Modelling

Task modelling aims at building task models of Human Computer Interaction.
Task modelling is a widely used tool in HCI. In the first place, it enables developers to gather and organise end-users requirements, and then to get a clear and general picture of the functionalities that are going to be offered, as well as a clear representation on how these functionalities are going to be organised, one in relation to the other.

Task modelling assists in the design, analysis, implementation and evaluation of applications by:

- providing a common tool that can be used in development and understood by all members of a development team (software and usability engineers, graphic artists, industrial designers, managers, stakeholders, end-users, etc.),

- defining a visual form allowing easy use during discussion and group work, and

- developing an agreed common terminology between all parties making communication easier.

## How to Build Task Models

You can build a task model by hand, or using a task model editor, such as TAMOT. The TAMOT editor will allow you to create and manipulate the different elements that constitute the task model.

## What is a Task Model ?

A task model is a step by step description of a goal to achieve. The description consists of a hierarchical decomposition of a main goal into a set of sub-goals. Each goal is represented by a task or a set of sub-tasks that reflect the different ways to perform the goal.
The task model is constructed with 3 basic elements :

1. Tasks that represent goals
2. Links that connect tasks together
3. Boolean Connectors that express specific ranking between tasks.

There are two basic issues here : task model notation and task model editing.
Among many task model notations, a subset of the Diane+ formalism is supported by Tamot.