Which aspect is least important when defining success in an experiment?

When defining success in an experiment, the least important aspect is the number of failed attempts. This is because the process of experimentation is inherently about exploration and learning, often involving multiple failures before achieving success. The key focus should be on understanding why those failures occurred and how they inform future attempts. While failed attempts provide valuable data and insights, they do not directly measure the effectiveness or relevance of the experiment's outcomes.

In contrast, defining a clear outcome as outlined in the hypothesis is crucial, as it provides a target for the experiment. Similarly, comparing actual results to the hypothesis allows for assessment of the experiment's effectiveness and validity. Finally, the engagement level of participants can be an important indicator of how well the experiment is received and whether it achieves its intended purpose. Therefore, focusing on the quantity of failed attempts detracts from the overall goal of learning and deriving meaningful results from the experiment.