Good guidelines often need to draw upon a range of knowledge sources: RCTs may be unavailable or not even provide the most suitable knowledge. Although a range of useful tools has been developed for grading RCTs, methods for appraising and including knowledge from other sources are in earlier stages of development. Experiences with such methods are not always shared and by remaining local, learning opportunities among G-I-N members are missed. This G-I-N Working Group (WG) tries to contribute to bridging this gap in methods for Appraising and Including Different Knowledge. If you are compelled to contribute to this as well we’d say: welcome to AID Knowledge!