A method, system and software for assessing an entity (15) at a first user terminal (13) connected to a data network (10). A control system (11) is used to receive an access request (101) from the entity (15) or an assessing user (16) at a second user terminal (14). The control system (11) invokes or facilitates transmission of a time-delimited sequence of unpredictable prompts (18) to the entity (15) for a performance of visible prompted actions (20). A video recording (21) of the prompted action performance is stored in a data store (61) and the control system performs an automated assessment of the video recording (21) by a gesture recognition system (67d) and generates an assessment signal respectively including a positive or negative indication of whether or not said entity (15) validly performed said prompted actions.