When training, I hate using ‘foo’ and ‘bar’ in examples. It means I’m ignoring a major portion of my responsibility – relating the Rails concepts I’m teaching to the problem my students are trying to solve.
For example, let’s say you are training students that are building an application for managing project teams. When teaching RESTful webservices, try explaining how a resourcefully-built web application could provide a free API for retrieving information about the project team members. The team members could be displayed on a totally separate web application by simply exposing these teams of people as bona fide resources.
The example might not be completely relevant - they might not need to connect to other web applications. It might shine light on another problem they need to solve - can we do the same for sharing the project schedules?
In the end, it makes my students more productive. They focus on solving their biggest problems and not just learning all of the Rails concepts.