1. A computer-implemented method comprising: identifying, using one or more computing devices, a field in a set of forms and strokes included in the field; determining, using the one or more computing devices, distance metrics between the strokes; creating, using the one or more computing devices, a hierarchical cluster for the strokes included in the field based on the distance metrics; receiving a search query from a first user, the search query including a first stroke extracted from the field of a form filled out by a second user; retrieving, using the one or more computing devices, a cluster from the hierarchical cluster and example strokes of the cluster similar to the search query; providing the example strokes to the first user; receiving, from the first user, a selection of a first example stroke from the provided example strokes; and responsive to receiving, from the first user, the selection of the first example stroke, retrieving a table listing a number of forms in the set of forms that were filled out by the second user and have strokes similar to the first example stroke.