Information processing apparatus and control method therefor

Input interpretation information describing rules for interpreting the intentions of inputs is held in an indication input interpretation grammar holding unit. An input to a coordinate input region is detected by a pen input detection unit. The intention of an input detected by referring to the input interpretation information is interpreted by a grammar parsing unit. The confidence score of the interpretation result is calculated by a confidence score calculation unit. A certainty-factor-attached N-best output unit outputs the interpretation result together with the confidence score.