DIFFERENCE CALCULATION PROGRAM, DIFFERENCE CALCULATION DEVICE, AND DIFFERENCE CALCULATION METHOD

摘要

Out of information contained in Web pages at different times, difference information on only specific information required by a user is calculated. A Web page collection part in a difference calculation device collects the Web pages according to a search key. An information extraction part extracts store names, addresses and telephone numbers to be extracted from the collected Web pages. An extracted information adjustment part adjusts the extracted information containing the extracted store names, addresses and telephone numbers. An extracted information storage part stores the extracted information in an extracted information file. A difference calculation part carries out difference calculation processing of calculating the difference between pieces of the extracted information belonging to respective two periods to be compared when the two periods to be extracted are designated. A calculation result display part displays a difference calculation result on a monitor.