The present invention concerns a method for an artificial neural network to confirm the recognition of handwritten characters produced by a user. The method comprising: training (21) the artificial neural network with a training data set comprising a first set of characters; collecting (23) handwritten characters of a second set of characters produced by the user; and analysing (25, 27) the collected characters of the second set of characters by using the artificial neural network to obtain a first set of probability values comprising character specific probability values for the collected characters, each character specific probability value indicating the probability that the collected character has been correctly interpreted. The analysis considers at least the manner how the collected characters are handwritten and the appearance of the collected characters to obtain the character specific probability values. The invention also relates to a corresponding data processing apparatus.