This might be due to: (a) our use of @-mention features; (b) l 1 regularisation, which is essential to preventing overfitting for large feature sets; or (c) our use of l 2 normalisation of rows in the design matrix, which we found reduced errors by about 20% on GEOTEXT, in keeping with results from text categorisation (Lee, 1995).
there is no clear consensus on whether text-or network-based methods are empirically superior at the user geolocation task.