Abstract: A mobility movement information acquiring method has: acquiring an observed velocity value of a mobility according to a first interval; storing the observed velocity value and corresponding time information so as to relate each other; and acquiring an acceleration value in a travelling direction by inputting the observed velocity value into a state-space model in which: displacement per unit time of a state velocity value is the acceleration value in the travelling direction, the observed velocity value is a sum of the state velocity value and a value following a first distribution, and displacement per the unit time of the acceleration value in the travelling direction follows a second distribution.