Find Compatible Single Men or Women Near You – The relationship experts at eharmony’s headquarters in Los Angeles studied thousands of couples, working to understand what creates a happy, long-lasting relationship. As a result, it became clear that certain key characteristics can predict compatibility and lead to more satisfying relationships. Unlike other dating sites, eharmony requires its members to complete an in-depth questionnaire whose results are used to determine singles’ personality at the core to deeply match based on key areas of compatibility.