Of course we wanted a particular thing but we are not always in a position to be very exacting in the kind of person we want. We may be inclined to accept someone who then turns out to be inappropriate.

If it's formal, you plant soil. You plan the time the person should be here and when he/she is needed most, and you plan the curriculum and the topics. So they also come prepared and send someone who is an expert.

I think what makes them effective is …structure. We need to give them structure, so it’s not like they have to make up what they want to give. We need to articulate our needs very clearly. Sometimes we do that by extracting from the curriculum and giving it to them beforehand, and thus communicating with them exactly what we want to achieve and then they are more likely to do the right kind of preparation or they have the right expectations.