We've been noticing a lot of mentorships have not been getting off the ground, largely because editors drop off quite soon. Even when they are matched, and their mentors attempt to engage them, they do not respond. For example:
In total, I've documented 15 cases where a mentor initiates discussion with a learner, but the learner does not reply. Many of these cases seem to be with editors who are very new to Wikipedia. Conversely mentorships that have resulted in interactions appear to with learners who are a little more established:
@Soni and I suspect that mentorship is perhaps better suited for editors who have done a little editing and had their accounts longer than a day. I also think that mentors should not be investing their time in editors who do not appear likely to reply.
For these reasons, we think it would be best to have HostBot restrict sending invitations to editors with accounts that are at least three days old, and have edited recently (however that is defined by HostBot currently) I'm open to other suggestions about edit counts, as these were somewhat arbitrary numbers that Soni and I developed, but we do want to better target editors who are likely to benefit from mentorship, of which many from our current pool do not due to attrition.
@Halfaker - I'm CCing you on this as well, as I suspect this will reduce the number of invitations we send out, and likely, the number of incoming editors for any studies that are being done with Co-op invitees in mind.