Since websites are dynamic in nature, much research [10, 11] has focused on creating robust extraction patterns that will continue to work even after a document has been updated. Methods that use relative paths within the Document Object Model (DOM) are generally more robust than those that use absolute paths. As stated in the survey by Laender et al. [11], popular methods for defining extraction rules include XPath, XQuery, and CSS selectors, while some systems utilize heuristics, ontology, natural language processing, or machine learning techniques to identify which pieces of information to extract.