spaces rather than just one, and with frames of reference that are deeply embedded in our assumptions about the shared experiences of our listeners. Our use of figurative language to explain how to use our technologies will be effective only when our listeners (or readers or users) apply the appropriate (and disregard the inappropriate) properties from the various input spaces, and when they really have had the antecedent experiences required by the frames of reference we employ.

Blends can be seen as a conceptual space in which understanding does or does not occur. In describing the Internet as a series of tubes, Stevens created a blend that correctly highlighted the similarities of the tubes/ pipes input domain, namely, the properties of length, diameter, joints, etc. He created appropriate structure for the blend by drawing upon a universal “conduit” frame in which information travels from one point to another. But he also applied inappropriate properties from the pipes input: for instance, the idea that pipes can be filled to bursting or clogging, or that they present a single path from A to B. His blend was overdetermined by the “pipes” input to the detriment of his overall understanding. (A similar phenomenon is evident in Stevens’s rhetorical question, “Ten movies streaming across that, that Internet, and what happens to your own personal Internet?” “Personal Internet” may be a beautiful oxymoron, but it is also the result of a blend that is overdetermined by the “ personal computer” input, itself an interesting blend). If we mocked

Stevens’s comments, it is mainly because we have access to other inputs—many of them also blended constructs such as “World Wide Web,” “ store-and-forward packet switching,” or “routers”—that help us better conceptualize how Internet traffic is managed.

Blends are a natural part of how the human mind works. Turner and Fauconnier argue that blends have defined human thought since the advent of language, approximately 50,000 years ago. So when we use figurative language to help people understand new technologies, we need to be aware of how blends function. Moreover, we must avoid metaphors that inadvertently encourage blends that impede usability.

The concept of an e-book or e-reader has already become almost meaningless as a result of marketers’ failure to consider how their metaphors will play out as blends in the minds of users. In this metaphor customers are expected to apply what they know about traditional books and electronic media to a new product, the electronic book. The blend that results borrows known properties of books (they have numbered pages that can be turned; they are shelved with other books in libraries, etc.), and known properties of digital texts (they can be delivered electronically; they are full-text searchable; etc.). The resulting blend should then define for the user the imagined properties of the new device. In an ideal situation, the result is improved usability, with the blend representing those properties of each source that are relevant to understand-