discuss every experimental approach being pursued, but instead focus on several of the most promising direct, indirect and collider efforts, and on the interplay and complementarity between these various programs.

We would like to emphasize that the detection of dark matter particles in any one of the experimental channels discussed here will not alone be sufficient to conclusively identify the nature of dark matter. The direct or indirect detection of the dark matter particles making up our galaxy’s halo is highly unlikely to provide enough information to reveal the underlying physics (supersymmetry, etc.) behind these particles. In contrast, collider experiments may identify a long-lived, weakly interacting particle, but will not be able to test its cosmological stability or abundance. Only by combining the information provided by many different experimental approaches is the mystery of dark matter’s particle nature likely to be solved. Although the detection of dark matter in any one search channel would constitute a discovery of the utmost importance, it would almost certainly leave many important questions unanswered.

THE WIMP HYPOTHESIS
===================

In this review, we limit our discussion to dark matter candidates which are heavy, electrically neutral and weakly-interacting. This class of particles, collectively known as WIMPs, 