I usually take the "I don't know, but I would like to take a stab at it anyways" approach to interviews. I make my competence on a subject clear. Ie. Did an as

I usually take the "I don't know, but I would like to take a stab at it anyways" approach to interviews. I make my competence on a subject clear. Ie. Did an assignment using this tool or read a few blogs so am aware of it and that's it. But a surprising number of times the problem isn't thay difficult despite my ignorance about it. You can often find a very close analogue to the unknown thing and then take it from there or let the tool itself function as a black box and design the requested system around it. The plain "I don't know" - er while noble, can often be mistaken for incompetent when every other bulshitter claims to know it all.