Greater than the sum of the parts

IDEA N^o 81

MASHUP

The Marauder’s Map plots every inch of Hogwarts and pinpoints every person in the school, even the ghosts. In the same way as The Daily Prophet foresaw the iPad, the Marauder’s Map is a magical realization of the mashup.

A mashup is a Web-based application that uses two or more sources to create a new, hybrid service. One of the first mashups was developed at the University of Edinburgh in 1994. The World Wide Earthquake Locator used data from the National Earthquake Center and displayed it on the Xerox PARC Map Viewer. The result was a map that plotted up-to-date earthquake information within hours of it happening.

But mashups really took off in 2005. Enterprising hackers created housingmaps.com, a site plotting room rental ads from Craigslist on Google Maps. Google saw the potential and released an Application Programming Interface (API) that allowed inventive developers to manipulate Google Maps in creative ways. A flurry of mashups followed. Historypin is a user-generated archive that invites people to pin historical photos, videos and audio recordings to Google Maps. Trendsmap. com is a global map of Twitter hashtags. Pothole Season tells you where all the potholes in Canada are and provides routes that avoid them. The Season Phenology Visualization Tool displays sightings of plants and animals across the US.

But not all mashups involve maps. Amazon, eBay, Foursquare, Flickr, Last.fm, Spotify, Twitter, Wikipedia and YouTube all provide APIs. Sonar combines Twitter, Facebook and Foursquare to alert you if your friends are nearby. The Royal Observatory combines Flickr images with Astrometry.net data to create a comprehensive photographic record of the night sky. Aaron Koblin’s ‘The Wilderness Downtown’ uses Google Street View to create a personalized video for Arcade Fire’s ‘We Used to Wait’.

As more and more platforms open their data streams, we get closer to the Semantic Web envisioned by the fathers of hypertext, Vannevar Bush, Ted Nelson and Tim Berners-Lee. The potential of shared data is enormous (see Big Data). It can help us to predict earthquakes, map the night sky, make incredible pop videos and almost anything else we can imagine. Plotting ghosts on a map may be a way off yet, but mashing up data really can create equally magical results.■

‘As more and more platforms open their data streams, we get closer to the Semantic Web. ’

The Museum of London’s Street Museum app lays historical pictures of images over present-day scenes.