From the Ideo website:
IDEO Method Cards is a collection of 51 cards representing diverse ways that design teams can understand the people they are designing for. They are used to make a number of different methods accessible to all members of a design team, to explain how and when the methods are best used, and to demonstrate how they have been applied to real design projects.
IDEO’s human factors specialists conceived the deck as a design research tool for its staff and clients, to be used by researchers, designers, and engineers to evaluate and select the empathic research methods that best inform specific design initiatives. The tool can be used in various ways—sorted, browsed, searched, spread out, pinned up—as both information and inspiration to human-centered design teams and individuals at various stages to support planning and execution of design programs.
Inspired by playing cards, the cards are classified as four suits—Ask, Watch, Learn, Try—that define the types of activities involved in using each method”