Abstract: We present a design space explorer for the space of experimental designs. For many design problems, design decisions are determined by the consequences of the design rather than its elemental parts. To support this need, the explorer is constructed to make the designer aware of design-level options, provide a structured context for design, and provide feedback on the consequences of design decisions. We argue that this approach encourages the designer to consider a wider variety of designs, which will lead to more effective designs overall. In a qualitative study, experiment designers using the explorer were found to consider a wider variety of designs and more designs overall than they reported considering in their normal practice.