A reference size when data of a data field is laid out in a page is decided on the basis of the data display sizes of data fields having the same data field name in a plurality of types of records. A data field having a data display size corresponding to the decided reference size is chosen from the data fields having the same data field name in the plurality of types of records. Data of the data field is laid out in the page on the basis of the data display size of the chosen data field.