Are you ready for your first encounter with web scraping? Let us start with a small example that you can recreate directly on your machine, provided you have R installed. The case study gives a first impression of the book's central themes.
1.1 Case study: World Heritage Sites in Danger
The United Nations Educational, Scientific and Cultural Organization (UNESCO) is an organization of the United Nations which, among other things, fights for the preservation of the world's natural and cultural heritage. As of today (November 2013), there are 981 heritage sites, most of which of are man-made like the Pyramids of Giza, but also natural phenomena like the Great Barrier Reef are listed. Unfortunately, some of the awarded places are threatened by human intervention. Which sites are threatened and where are they located? Are there regions in the world where sites are more endangered than in others? What are the reasons that put a site at risk? These are the questions that we want to examine in this first case study.
What do scientists always do first when they want to get up to speed on a topic? They look it up on Wikipedia! Checking out the page of the world heritage sites, we stumble across a list of currently and previously endangered sites at http://en.wikipedia.org/wiki/List_of_World_Heritage_in_Danger. You find a table with the current sites listed when accessing the link. It contains the name, location (city, country, and geographic coordinates), type of danger ...