[Jump to Explorer FAQs]

Q. What are TagMaps?

A. TagMaps are a new way to visualize text on geographic maps. TagMaps can be used to communicate key characteristics of location-based data in an easy-to-understand way.

Q. What are examples for use of TagMaps?

A. Hopefully, the sample applications above can give you an idea. To give other examples, you can use TagMaps to display the most popular movies in your country (perhaps show movie names over the cities in which they are popular), show Flickr user names of the users that took the most interesting photos in each geographic region, show the names and distribution of bird species,... have better ideas? let us know: tagmaps-feedback [at] yahoo-inc.com!

Q. Cool! Can I use TagMaps for my blog/website/beauty salon?

A. Yes. TagMaps is available as a flash component you can embed on your blog. You can plug in any source of data to your blog's Tag Map - whether it is the data sources we provide (like World Explorer), data sources you create, or other sources you find on the web.

Q. What is the World Explorer?

A. The World Explorer is a new and (we hope) exciting way to explore the world while browsing real users' public photos, using TagMaps. The Explorer is based on photos users upload to the Flickr website. The World Explorer engine analyzes the information tied to the photos (such as location and tags) to find the main "attractions" in each location and in every zoom level and compute their "importance". We use the tags, on the map, in varying font sizes, to represent these attractions. For World Explorer, we augmented TagMaps with a Flash widget that displays the actual photos from that location, so you can get an idea of what you can see from there. Think of World Explorer as the automatically-generated, visually-rich guide to the planet. It's not Yahoo! Earth. It's the REAL Earth (you are welcome to read more about the technology behind World Explorer on our blog).

Q. How do I use the World Explorer?

A. Move the map around, zoom in, zoom out, search for a place - check out the tags in various map areas. Now, move your mouse over one of these tags - no need to click - photos from that location that are tagged with the highlight tag will show up on the right. You can click to enlarge this photos, or to view them on Flickr. You will also notice that some tags have an attached list of additional tags the shows up on mouse over - these are additional tags that are important at that location. Hover over a related tag with the mouse to see the respective photos.

Q. Why do tags appear in different sizes?

A. The size of the tags on the World Explorer (and in TagMaps in general) reflects their importance. The bigger the tag, the more "important" it was deemed by our algorithm for that location and the given zoom level. The tags and their importance computation factors in measure such as tag frequency, uniqueness, user identity and social factors - the exact formula will be kept in our Yahoo! Research vaults. In fact, we have fed that piece of paper with the formula to our lab's goat, so we don't even know what it was any more.

Q. There were no tag on the map area I was looking at / tags were wrong or didn't make sense / my favorite landmark is missing from the map - what gives?

A. World Explorer tags are generated automatically, based on geotagged images on Flickr and tags associated with those images. The algorithm we run decides, based on that data, which places to feature and which tags to feature in these areas. So there are a two main reasons why it's not perfect: a. Some places in the world don't have enough data (or do not have accurate-enough data). b. The algorithm is not perfect (we all make mistakes). You can help fix this situation by taking more photos and uploading them to Flickr - don't forget to geotag and add text tags to those photos!

Q. What's the connection between World Explorer and ZoneTag?

A. ZoneTag is Yahoo! Research Berkeley's prototype location-aware cameraphone application. ZoneTag can upload geotagged images from your phone directly to Flickr; one connection is that the ZoneTag images are part of the data (together with all other Flickr geotagged images) used for World Explorer. So, ZoneTag helps the data - but the data also helps ZoneTag! What does this mean? Well, see how the World Explorer shows you tags over some map locations? Now, imagine that you are physically standing in that location, snapping a photo with your phone. There's a pretty good chance you took a photo of one of the items represented in the World Explorer tags. ZoneTag will suggest these tags to you right after capture - so you easily tag it (and thus be able to find that photo later, as well communicate that info nugget to your Flickr friends). ZoneTag does all this and more - and it is available for Nokia and Motorola phones. What are you waiting for? Check out ZoneTag.

Q. How can I contribute to World Explorer?

A. You may have contributed already! If you have a public, geotagged image on Flickr, then it was part of our computation. If you added tags to the photo, these tags were also analyized - and your photo might appear in the visualization (look for it!). We update our tag maps every few weeks, so newly uploaded photos could influence the next version of World Explorer.

Q. I wonder - do you collect any data from this research prototype?

A. You bet! Your interactions with the system are anonymously recorded and analyzed in order to improved the experience for you and other users who are using TagMaps and World Explorer. That's what research is all about!

Q. Great! I am going to print a map of the area and use it for navigation.

A. Are you out of your mind??? TagMaps should not be used for navigation under any circumstances. The location of the tags shown on the map is not only approximate, but also derived from user content. As we all know, user content is great and all, but sometimes it is just not accurate. So, after you get inspired, make sure the landmarks are really there (may we suggest Yahoo! Local or Yahoo! Travel?).

Q. OK, so what is Night Explorer?

Same same, but different. Night Explorer is based on the exact same idea, only our computation only take into account Flickr photos taken at night. Will night photos have different tags than daytime photos? Check and see! We think we see more night clubs and "cool neighborhoods" come out of the night data. By the way, notice that there are significantly fewer photos at Flickr taken at night - the visualization for Night Explorer will therefore be somewhat sparser in many areas.

Q. But you're still showing me day photos in Night Explorer, what gives?

You know how you never set the time on your digital camera? Well, that really grinds Night Explorer's gears. To pull out night photos, it looks at the photo time and the upload time. So, it's obviously not a foolproof algorithm and it's made harder by the fact that it's a pain to set your digital camera time. We've got something cooking that will hopefully help you solve the time issue, so stay tuned.

Q. OK, so what is Trip Explorer?

Very different. Trip Explorer has nothing to do with Flickr, but amazingly, it is another place where the wisdom of the crowds (there, we said it) generates very similar results. Trip Explorer is based on items that appear in Yahoo! Travel users' public Trip Plans. However, instead of showing you the most popular spots, which you can find easily in any travel book or travel site, we mine each map area for the "fat middle" of travel spots. We present these trip planner items as tags on the map. The resultant Tag Map shows you the "hidden gems", places you may not normally discover if you're just reading about the hot spots for a location. Use Yahoo! Trip Planner to plan your next trip. Trip Explorer is US only right now.

Q. Cool! Can I use World Explorer for my blog/website/beauty salon?

A. Most definitely. Try here.

Q. Cool! I love all this data. Is there an API?

Yup. Of course. Check them out on Yahoo! Developer Network.

Q. Who did this? And why?

TagMaps and World Explorer were developed at Yahoo! Research Berkeley as part of our mission to explore social media technology and applications that will enable people to create, describe, share, find and remix media on the web. Check out our web page for other items of interest.