How is a designer supposed to make rational decisions about the meaning and features of a product, system or service which will take 2, 3 or even 4 years to develop ? Society might be greatly different by then !
There will always be room for creativity and personal vision, but with development costs spiralling out of control there is a growing need to find ways to better ground decisions on customer and societal data which will still be relevant when the innovation reaches the market.
In recent years techniques which go by names such as critical design, speculative design and design fiction have been deployed as part of the effort to keep up with technological and behavioural innovation.
A recent NESTA blog provides a helpful overview of a few of these techniques for exploring the future.