1. A task selection assistance apparatus, comprising: task model storing means for storing one or more tasks each indicating an action to be taken by a user to solve his or her problem and one or more pieces of attribute information each indicating an attribute of a task, the stored one or more tasks and the stored one or more pieces of attribute information being associated with each other; attribute candidate determining means for determining one or more attribute information candidates to be presented to the user from among the one or more pieces of attribute information stored in the task model storing means; user selected attribute obtaining means for obtaining one or more pieces of attribute information selected by the user from the one or more attribute information candidates determined by the attribute candidate determining means; and task candidate determining means for determining one or more task candidates to be presented to the user from among the one or more tasks stored in the task model storing means, based on the one or more pieces of attribute information obtained by the user selected attribute obtaining means.