A server inputs behavior information of a target to a trained machine learning model that learn a plurality of association relations obtained by associating combinations of behaviors generated from a plurality of behaviors included in a plurality of training data items with likelihoods indicating certainties that the combinations of the behaviors are in a specific state, the trained machine learning having been trained by using the plurality of training data items obtained by associating combinations of behaviors of persons corresponding to the specific state. The server specifies a difference between the combination of the behaviors in each of the plurality of association relations and the behavior information of the target based on output results of the trained machine learning model, and determines an additional behavior for causing the target to transit to the specific state based on the likelihood the difference.