I’m a strong advocate of sketching as a critical and fundamental design skill, as noted here. For me, sketching is not cool artwork, but a great rapidly visual way of processing information, working through problems, exploring lots and lots of ideas very quickly and fluidly. It’s not about “the perfect drawing” at all, which I think perplexes some IxD’ers (mainly those from HCI or CS, i think?) for some reason who refuse to sketch or think it’s not in their purview to do so. How can one design solutions without sketching (even if you’re designing systems/services/processes, etc.)?

Thankfully Jason Santa Maria iterates this point with his wonderfully concise and visually appropos posting here.