Tests that show machines are closing in on human abilities

It may have been dreamt up in 1950, but the Turing test - a simple way to tell if a machine can think - still holds powerful sway over many researchers striving to produce a machine at least in some respects equal with a human.

Nowadays, although UK mathematician Alan Turing's test is still relevant, and unbeaten, new forms of it have evolved. In this online special, New Scientist discovers the different ways in which machines can be tested for human-like abilities - and how close they have come to passing as one of us.

1. Turing Test - The Turing test, developed by Alan Turing in 1950, is a test of a machine's ability to exhibit intelligent behaviour equivalent to, or indistinguishable from, that of a human.

2. Alan Turing - Alan Mathison Turing OBE FRS (23 June 1912 – 7 June 1954) was an English computer scientist, mathematician, logician, cryptanalyst, philosopher and theoretical biologist.