Improving Mobile Search for Cities
Our first-generation mobile search algorithms often use simple “expanding radius searches” around specific points. Here’s what happens: If you were to conduct a search for pizza in Chicago, IL, we would search within a 5-mile-wide circle around a central point in Chicago for businesses related to pizza. If no results are found we would expand the radius by an additional 5 miles, until we find results or reach the maximum search radius of 20 miles. The same goes for ZIP codes, neighborhoods and street addresses.
The problem is that for some cities (not so much for ZIP codes and neighborhoods), this simple approach can sometimes omit businesses that actually fall within the city, but don’t fall within the circle we’ve drawn on the map. This is especially perplexing for users who search for a business that they know is in a certain city, only to discover that they can’t find it using one of our mobile apps.
A simple improvement to this algorithm is to combine the basic idea of a radius search with a search for businesses with addresses that match the city name. We call this search algorithm “Box+ search”. We expect this new dual approach to provide more accurate search results than the “expanding radius search”. To validate this we have set up a page where you can see the results of the two approaches side by side. You can see the difference in search results by looking at the following links, or try ‘Box+ Search” search with your own terms and location:
- Thai Food in Pasadena, CA
- Apple Stores in New York, NY
- Day Spa in Malibu, CA*
- Auto Parts in Sierra Madre, CA
- Massage in Sammamish, WA
Note: For uninteresting technical reasons, the search actually finds matching businesses using a box, rather than a circle, along with the name of the city, neighborhood or zip code.
The blue pins are businesses that were only returned in the “expanding radius search”. The red pins are businesses returned with “Box+ search”. The green pins represent listings that were returned by both search algorithms.
The red box shows the default area that was searched for Box+, while the blue circle shows the expanded radius search area.
* This result is interesting because it shows how a Box+ Search returns accurate results i.e. business that are “Day Spas” in “Malibu, CA”, where as the radius search returns businesses in similar categories but closer to the center of the specified search area.