A think tank is an institute or organization that performs advocacy and research on one or more topics. Think tanks frequently address topics like proposed political and social policies, economic matters, use of technology, and culture. The structure and goals of a think tank often reflect its source of support, which can be anything from a non-profit to a government-, corporation-, or university-sponsored guarantee of support. Think tanks range from large and diversified groups to smaller setups focused on specific and specialized topics. Some think tanks provide help with writing legislation, finding experts on particular issues, determining what topics should be studied, or bringing people together.