Postcode or radius: Which works better in matchmaking?
Location based Match-Making
A standard function of online platforms is the circular search. The two most common approaches are the use of postcodes (PLZ) or the radius search.
The problem: Postcode search combined with a radius search.
We were presented with an interesting problem: A job is posted on a platform, specifying the location and a desired work radius. The system should then automatically detect which postcodes are within this radius and assign them to the job.
The difficulty lies in the fact that postcode areas often have irregular shapes and a given radius only covers parts of a given postcode.
For example, if a job is posted in 53111 and specifies a radius of 5 km, this radius may overlap parts of 53119 even though most of 53119 is outside this radius. A job seeker from 53119 could then see the job as available even though it is not actually in their area.
The Solution
Mixing radius and postcode can lead to inaccurate or misleading search results. Therefore, here are some suggested solutions:
Radius search only: Platforms should only offer a radius-based search (radius search). Job seekers could then enter their exact location (e.g. their address and the desired maximum radius) and the platform could display the jobs that are available within that radius. Mixing postcode and radius searches is not recommended because it can lead to unexpected results.
Travel time-based search: The Google Maps Distance matrix allows you to determine the travel time by different means of transport for two or more points. Job portals could, for example, offer the function that searchers filter for jobs that can be reached by public transport within a maximum of one hour.
Conclusion
A radius search should deliver comprehensible and accurate matching results. For this purpose, it should be clearly communicated how it is matched, for example, exclusively on the basis of the user's location and the set radius.
The following is a simple example that describes and illustrates the problem with real addresses.