A while ago I finally had the chance to do the marshmallow challenge. I learned a few things, but not the things I expected to learn. I feel it might be worthwhile to share these learnings.
The marshmallow challenge is a team-building exercise. Each team gets a yard of rope, a yard of tape, a bunch of uncooked spaghetti noodles and one marshmallow. With just these materials each team has to build a structure holding the marshmallow as high as possible, in 18 minutes.
Our team consisted of three people. Each team would do the marshmallow challenge twice, with a retrospective in between so that the learnings of the first round might be applied in the second round.
I had read about the challenge on the internet and knew that young children performed best at it, because they simply started doing instead of trying to come up with a detailed plan beforehand. So, during the first round I suggested a simple approach to start off with and then just dived right in.
One other person on the team went along with my idea, but the remaining team member had a different idea. I mostly ignored those suggestions and stuck with my initial strategy, because I didn't want to lose time arguing.
Obviously, this was a mistake. This team member tuned out and stopped cooperating, wistfully looking at the work of the other teams who did implement his strategy or something similar. Although those teams failed miserably, so did we, and we had to scramble in the final minute to get the marshmallow just a few inches high. At least we had a result, some teams had nothing at all. Small consolation.
During our retrospective we concluded that whatever strategy we would choose, we all had to agree to it, even if that meant spending a few minutes getting to that agreement. I acknowledged that I should be more open to other people’s ideas and the other team member agreed to be more cooperative even when their idea wasn’t fully adopted.
Lesson learned #1: before embarking on a mission, make sure to have buy-in from all team members on the approach you will take. If this takes some time, then so be it. You can’t skip this step.
We also discussed how we would approach the technical side of building the structure in the second round. We agreed that we would try an incremental approach. We would first build a single story with the marshmallow on top of it and focus on making it sturdy, then add the next story underneath the first one, and so forth. We could stop when time was running out, or when we felt adding another story would be too risky, or if we ran out of materials to build another story. Assuming we would finish at least one story, we would have a result.
This time we were asked to estimate the height of our marshmallow for round 2. Adhering to the idea of empiricism we estimated the result to be the same as in the previous round.
As we were able to apply the learnings of the previous round we did much better this time. We finished two stories and were able to more than double our result from the previous round. We finished a few minutes early and decided to not to risk adding another story, even though this structure was a lot sturdier than the one from the previous round.
The fact that we decided to use an incremental strategy had a few interesting effects. If you have an effective way of creating valuable increments within a small timeframe then there is no need to time box it. Indeed, it might even be wasteful to do so. However, if you cannot create a valuable increment within a small timeframe then time boxing might be a way to get to the point that you can. Once you reach that point, however, it might be more effective to ditch these training wheels.
Lesson learned #2: time boxing becomes obsolete when using an effective incremental approach.
Also, the estimating we did in between rounds seemed silly in retrospect. We knew the materials we could use and the maximum amount of time we had to do the job. What did it matter what we had estimated? Providing an estimate did not make us more efficient or provide value in some way. Exceeding or falling short of the estimate did not define success, only the final result mattered.
Using an incremental strategy we were able to achieve the best possible result in the allotted time. It also allowed us to mitigate risk as we were more confident that we would have a result when time ran out. We could continually evaluate whether it might be worth it to add another story to the structure.
Lesson learned #3: estimating becomes obsolete when using an effective incremental approach.
Summary: the marshmallow challenge is a fun and quick way of learning to work together on a task you have never performed before.
- Take the time to assure buy-in from all team members on the approach to take
- Use an incremental approach to produce results quickly and mitigate risk
- An effective incremental approach makes time boxing unnecessary
- An effective incremental approach makes estimating less useful