Recently, task-based computing (TBC) paradigm has gained acceptance as the choice computing model for pervasive computing environment. One of the key components of TBC is a task model that provides an adequate high-level description of user-oriented tasks. This paper presents a novel context-sensitive task modeling approach capable of supporting complex, user-oriented task definitions. This work is motivated by the fact that whilst current TBC systems allow users to interact with their ambient environments in terms of high level tasks, existing task definitions are still relatively simple, and do not include user-centric and environmental contextual information in the task definition. This paper elaborates the proposed task model through a smart home application example to illustrate steps in context-dependent task modeling, service provisioning and resource organization.