Define data extraction rules

The information extracted from Web pages with MetaSeeker are classified into two categories: data snippets and clues. They are extracted by DataScraper which is driven by data extraction instruction files and clue extraction instruction files respectively. In summary, if operators want to extract data snippets, they have to define data extraction rules with the help of MetaStudio, which is stated in this chapter. In contrast, if they want to extract rules, they have to define clue extraction rules, which is stated in next chapter.