19. A device control method, comprising: performing, in a computer: a speech recognition step of acquiring speech data representing a speech and specifying words candidates included in the speech by performing speech recognition on the speech data and calculating a likelihood of each of the specified words candidates; a specifying step of specifying words included in the speech based on likelihoods specified in the speech recognition step and specifying a content of the speech uttered by an utterer based on the specified words; and a process execution step of specifying content of a subsequent control to be performed on an external device to be a control target based on a currently executed control, a predetermined subsequent control, a weighting factor associated with the currently executed control, and the specified content of the uttered speech, and performing the subsequent control, wherein the process execution step obtains the weighting factor by calculating a product of transition constants defined on routes from the currently executed control to the subsequent control associated with the currently executed control, and, among the subsequent controls associated with the currently executed control, identifies a control in which a product is a largest product of the weighting factor and the calculated likelihood.
19. A device control method, comprising: performing, in a computer: a speech recognition step of acquiring speech data representing a speech and specifying words candidates included in the speech by performing speech recognition on the speech data and calculating a likelihood of each of the specified words candidates; a specifying step of specifying words included in the speech based on likelihoods specified in the speech recognition step and specifying a content of the speech uttered by an utterer based on the specified words; and a process execution step of specifying content of a subsequent control to be performed on an external device to be a control target based on a currently executed control, a predetermined subsequent control, a weighting factor associated with the currently executed control, and the specified content of the uttered speech, and performing the subsequent control, wherein the process execution step obtains the weighting factor by calculating a product of transition constants defined on routes from the currently executed control to the subsequent control associated with the currently executed control, and, among the subsequent controls associated with the currently executed control, identifies a control in which a product is a largest product of the weighting factor and the calculated likelihood. 21. The device control method according to claim 19 , wherein the process execution step specifies a process to be performed based on the specified content of the uttered speech.