A method of detecting tasks performed by users wherein a single task is a sequence of web URLs invocation. Task patterns are detected in web logs to identify tasks performed by users and analyze task trends over time, across corporate divisions and geographies. A grammar-based framework is used to model and detect tasks from web log patterns. The framework has two components: a declarative unit—to generate a task grammar, and a processing unit—to detect tasks from access logs by generating a state machine for applying the task grammar to the tokens associated with the access records. By analyzing user tasks, rather than just URLs, useful business information can be extracted.