When working on an agile development project, how do you incorporate into the estimation of time for user stories/use cases/etc. the time it takes to train new developers on unfamiliar technology being used by the project?? How do other managers handle this?
Of course, my question assumes that one has deemed the technology in question necessary to complete the project successfully ... or perhaps it could be considered paying down a bit of technical debt!
You just guess.
Since you're working in short iterations, you know pretty quickly if your WAG is way off.
If you're off, you adjust for the next week's iteration.
Remember, agile an iterative process, with each iteration giving you more insight into the project.
But to get started, just make a good guess.
The iteration estimations will get better each week.
If we face something which is new to the whole team (or most team members), then we have performed sort of an investgation sprint, where we allow ourselves some time (timeboxed) to investigate/learn.
For smaller things, we add a timeboxed activity to the sprint backlog to allow training/investigation/experimentation.
In both cases, we simply subtract the time used so far from the estimated remaining time at the end of each day.
Our scrum master has a chart with suggested quotas for extending the estimates based on a number of such parameters (new technology, new team member and so on). Still, at the end of the day, they are still just guesses.
If you're using a brand new (to you) technology, I'd suggest that you cut your velocity by half as a reasonable attempt to estimate the velocity using the new technology. Eventually, you'll be able to actually both measure your new velocity and have it return to more normal levels as your team gets familiar with the new technology. Adjust future estimates based on feedback during the early iterations.
Pluralsight.com has an entire course dedicated to Agile Team Practices authored by David Starr. You can view the first few clips of each module here:
http://www.pluralsight.com/main/olt/Course.aspx?n=agile-team-practice-fundamentals
Here are a few other related free resources from Pluralsight.com as well:
http://www.pluralsight.com/main/whitepapers/teamculturewithteamsystem.aspx
http://www.pluralsight.com/main/screencasts/screencast.aspx?id=vsts08-continuous-integration
http://www.pluralsight.com/community/blogs/starr/default.aspx
Enjoy.