A hybrid machine/human computing arrangement which advantageously involves humans to assist a computer to solve particular tasks, allowing the computer to solve the tasks more efficiently. In one embodiment, a computer system decomposes a task, such as, for example, image or speech comparison, into subtasks for human performance, and requests the performances. The computer system programmatically conveys the request to a central coordinating server of the hybrid machine/human computing arrangement, which in turn dispatches the subtasks to personal computers operated by the humans. The humans perform the subtasks and provide the results back to the server, which receives the responses, and generates a result for the task based at least in part on the results of the human performances.