This article describes examples of reflection documented in a longitudinal research comprising two studies: a three-year three-stage study on technology project-based learning (TPBL) and a three-year two-stage study on engineering thinking (ET). Both studies used qualitative tools such as interviews, active observations, and document analysis. Reflections expressed by 10th grade pupils from eight high schools and 14 post-secondary school students who participated in the TPBL study as well as the reflection findings of experts and undergraduates from the ET study were used. The data analysis indicates that reflection is not generated on its own; it must be fostered. Reflection takes one of three forms: as a reaction to an irregularity or error made when working on the system design; conducted in groups that is inherent to the design process in industry; and from intuition that something may not be quite right, even though preliminary results seem to be correct.