Read the following pedagogical scenario describing a high school English language project.
A language teacher decided to implement ProjectBased Learning to explore environmental issues. Together, the teacher and the students formulated a compelling driving question: "How can our neighborhood reduce plastic waste?" For three weeks, students investigated local waste data, interviewed community members, and systematically reflected on their own learning through weekly journals. They received peer feedback and used it to refine their work throughout the project. In the end, the students compiled their findings into written reports, which were graded by the teacher and archived in the classroom cabinet. 

An analysis of this scenario reveals that, despite the collective efforts, the project was structurally incomplete because it lacked one essential element of Gold Standard Project-Based Learning. Which core element of Project-Based Learning was missing from this practice?