The advent of powerful and inexpensive electronic and computer technologies has allowed the development of fully automated experiments studying possible interactions between mind and matter. In the most common experiment of this type, a random number generator (RNG), based on electronic or radioactive noise, produces a data stream that is recorded and analyzed by computer software. A subject attempts to mentally alter the distribution of the random numbers, usually in an experimental design that is functionally equivalent to getting more "heads" than "tails" while flipping a coin. In the RNG experiment, design flexibility can be combined with rigorous controls, while collecting a large amount of data in a very short period of time. This technique has been used both to test individuals for psychokinesis and to test the possible influence on RNGs of large groups of people.