# What is a Task Model ?

A task model is a description of tasks used in HCI. Each task refers to a goal and a set of conditions and operations to achieve this goal. All the tasks in a model are related to each other in a tree that hierarchicly decomposes a main task in a set of sub-tasks.

The task model is constructed with 3 basic elements :

1. Tasks
2. Links
3. Boolean Connectors

There are two basic issues here : task model notation and task model editing.
Tamo is an editing tool that supports, among many task model notations, Diane+ formalism.