Retrieval accuracy is improved by causing a difference in layout from document to document to be reflected in retrieval at will. To achieve this, there is provided an information processing method for a case having a plurality of retrieval steps (S1209, S1211, S1212) of retrieving image data that is similar to an input document image, the method including a step (S1200) of inputting weighting information for weighting a degree of similarity calculated by each of the retrieval steps; a step of weighting the degree of similarity, which has been calculated by each of the retrieval steps, for every item of image data on the basis of the weighting information, and calculating overall degree of similarity; and a step (S1213) of displaying the similar image data based upon the overall degree of similarity calculated.