The need to structure the process, which I now recognize as being an inquiry process, seems like it ought to have been obvious, but it clearly wasn’t.
The clearest way to illustrate this is with our Extended Essay timeline for Year 12 (Grade 11) IB Diploma students, which similarly structures the inquiry process, but also, crucially, includes a number of targeted interventions to support students at key points during the inquiry process (see below).

Even with this additional structured support in place, the Extended Essay (or EPQ) remains a substantial and challenging undertaking students who are only 16, and it is difficult to see how students who are 3 years younger could conceivably manage with any less structured support when we were expecting essentially the same undertaking of them, only on a smaller scale.
While the evolution of the Individual Project would be both interesting and instructive, it would also be overly time-consuming now. It is, however, worth noting that Barbara Stripling’s model of the inquiry process, which is what FOSIL is based on, is supported by a continuum of “the literacy, inquiry, critical thinking, and technology skills that students must develop at each phase of inquiry over their years of school and in the context of content area learning” (2017, p. 52). Not only did this mean that students in Year 9 and Year 12 who were undertaking work that was essentially the same in nature were doing so using the same process, but the underlying continuum of skills enabled us to develop these skills systematically and progressively from Year 9 up to Year 12 and 13, and from Year 9 down to Year 7 and 6.
By 2020, the Individual Project had evolved to include greater support for the inquiry process through an Inquiry Journal rather than only an Investigative Journal, as well as through their Tutorial Programme (see below).


The full Inquiry Journals may be downloaded from the Resources page (see below).

I will detail the Individual Project more fully later.
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Stripling, B. (2017). Empowering Students to Inquire in a Digital Environment. In S. W. Alman (Ed.), School librarianship: past, present, and future (pp. 51-63). Lanham: Rowman & Littlefield.