This is something that we've actually talked a bit about, as mentors, on my team. We feel that there definitely is value in failure, and it's both a great teaching tool and a part of the Engineering process - even someone was well known as Edison took thousands of failed attempts before he created a commercially viable lightbulb. But even though there's value in failure, we can't ignore the value of success. Repeated and prolonged failure can be discouraging and take away from the inspiration we're all trying to impart. So it's important to have some success mixed in as well.
So, with my team we always try to ensure the students have a successful year. That doesn't mean we go to champs every year, or that we define success by playing on Einstein. A successful year is something you feel in the atmosphere in your teams pit. It's an excitement and hope for the future. You can have that even if your ranked poorly, and likewise you can miss it even if your ranked highly. The key is to set realistic, achievable goals that stretch the team just a bit.
From a practical standpoint, this means that during the build season we let them fail at various things that are correctable. We try our best to ensure they don't do something totally off the wall that will set us back several weeks. But if they cut something too short or drill a hole in the wrong place it's just material - there's more sitting in the corner and they can try again. Likewise if they haven't thought through a design far enough to see the upcoming problems, then we have. We talk A LOT about how we're going to be solving the problems they'll run into next week. A lot of the time, we can be ready with an easy solution to help them get around the problem when they realize it (a solution that is only provided after they've come up with ideas and are still struggling)... Sometimes we don't see a solution to the problem, so we raise the issue earlier to get them thinking about it, and to avoid spending too much time going down a path that isn't going to work.
Don't let anyone fool you - being a mentor is hard. It's hard to manage a teams expectations, abilities, and failures to ensure a n overall successful season, however you define that success... And that definition may be different each year as the teams situation changes, and is largely guided by the expectations you help to manage. But it's also a lot of fun
