There might be two kinds of products: either a tangible one, or a presentation of a solution to a problem or answer to a driving question. Students presenting their work in public can add greatly to a PBL project. When they have to present to a public audience different from their classmates and teachers, the performance bar raises, since no one wants to look bad in public. That is why students need to be very well prepared to make their work public.
Not only is there an impact on classroom and school culture, helping create a "learning community", but it is also an effective way to communicate with parents, community members, and the wider world about what PBL is and what it does for students.
Students get ready for the “public presentation” of their work with an authentic and wider audience, not only with their teacher and classmates.
Teacher and audience evaluate students' work.
However, people from the community may be invited to participate and share their views.