Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:The design approach is based on the Reactable [10] principles of a collaborative interface based on constructive building blocks with physical objects that trigger or modify sounds, and a lack of division of the interface into territories as a mechanism for promoting self-regulation of spaces [27].
Category: