What Is Scraping? The Basics For Everyone
By Susanne Webster On May 7, 2015
Scraping is the process of extracting data from one website and saving them in a different place—for instance, on a different website. This process can be done in several ways, manually or automatically, with the help of software. In many cases, scraping is also referred to as screen scraping, harvesting, or web scraping. The following article covers the basic of scraping.
Data from web scraping can be used in different forms and ways. For instance, many websites actively encourage their users to scrape the websites’ data and use these data on a third-party website. A good example is Google Maps, which encourages its users to scrape its data and integrate the data into their own websites. However, there are also many forms of illegal scraping, such as scraping when a website strictly forbids the use of its data. Such restriction can usually be found in the terms and conditions of a website. A third form is predominantly a grey area, like Twitter scraping. Twitter allows users to scrape data but limits the amount of extracted data to a certain number of megabytes per minute.
Techniques for scraping a website
There are several techniques for scraping data. The most common are presented here:
- HTTP manipulation: HTTP manipulation enables the harvesting of static and dynamic data from a website via an HTTP request.
- Data mining: Data mining is an automatic, programmed process which recognizes a website’s information according to predefined scripts and templates which contain embedded data. With the help of a so-called wrapper, data are transferred from one website to another. The wrapper acts as an interface between the two websites.
- Scraping tools: Depending on the nature of the scraping tool, different data can be extracted. Whether the data are single website-related information or full functionalities and structures, there are available tools for extracting them. In many cases, however, such tools are very costly and are worth the money only if you intend to pursue extensive data harvesting. Cheaper alternatives are available, especially for extracting social media data useful for all kinds of marketing activities.
- Manual copying: Even though there are a great variety of tools available, in many cases people still rely on the traditional manual copying. This is especially the case if website information is blocked against any form of automatic scraping tools, like robots.txt. In such cases, people usually rely on the help of overseas freelancers who provide data entry services.
Microformats: Another form of scraping is scraping and using microformats. Microformats are (referring to the terms of the semantic web) a more commonly scraped set of information. However, the technique remains mainly the same, and only the format of the extracted data is differing.
Usage of scraped data
As already mentioned, different forms of data can be extracted. This goes hand in hand with the fact that scraped data are used in a variety of ways. The following is only a small selection of typical areas of data usage:
- Web analytics: A great deal of all scraping activities are done in the area of web analytics. There are thousands of web analytics software tools out there, which scrape data from the web and provide their customers data about their web traffic and their competitors’. Since 2012, this area has been experiencing a major dip because Google increased its restrictions on scraping data from the web.
- RSS feeds: Through RSS, data from one website can be used and published on another. This can happen either with or without the consent of website owners.
- Marketing research: Tools like Twitter scraping tools make it easier for you to analyze your social media network as well as your competitors’. For instance, with the help of a Twitter scraping tool, marketers can extract data from their competition and directly approach their followers with alternative offers.
- Train schedules and other valuable traffic information are in many cases embedded in third-party websites or apps and serve as a supplement to the core offering.
As we can see, scraping can be done in any section of the web, and if you know about the basics and the possible areas of usage, you are already ahead of a great proportion of the Internet community.
Scraping Twitter can be used for getting quality followers or analysis of competition. You can do it by yourself or look for expert’s help, but the best thing is that you can start with downloading your own free Twitter report.