7. The intention estimating method according to claim 6 , wherein, the calculating the intention co-occurrence weight includes referring to intention hierarchical layer graph data in which said intentions are hierarchized and defined according to the relationship between said intentions to calculate said intention co-occurrence weight by using a weight which is defined for each of said intentions which constructs each hierarchical layer.
6. An intention estimating method of estimating a user's intention from the user's language input, said method comprising: slitting the inputted language into a plurality of morphemes and extracting, from the morphemes, one or more intention estimation units each of which is a unit on which an estimation of said intention is to be performed, each of the intention estimation units consisting of one or more morphemes; estimating a respective partial intention which indicates a respective intention for each of said extracted intention estimation units; calculating an intention co-occurrence weight having a value which depends on a relationship between said estimated partial intentions; and generating an intention sequence corresponding to said inputted language by using said estimated one or more said partial intentions, and generating an intention estimation result corresponding to said inputted language by using both a score showing a likelihood of said generated intention sequence and the intention co-occurrence weight calculated for said partial intentions which construct said generated intention sequence.