Some may say personal anecdotes are great, to the degree we can acknowledge the difference/distinction between this anecdotal evidence (our lived experiences), and empirical evidence (research studies). Not to say that research is necessarily more accurate...

Some families may have children in schools which are participating in grant-funded research, such as the experiments described in links upthread:
- gifted students may be in inclusive classrooms OR grouped by ability BUT receive the same curriculum, pacing, and measurement of growth regardless of group (with a measurement ceiling low enough to cause the reported measurement of the gifted students to be equal to the growth of the student body as a whole)

Additionally, reported experiences include anecdotes such as:
- gifted students may not be told test/quiz/assessment dates, while students in support programs may receive the dates of upcoming tests/quizzes/assessments, and also study guides for review of material to be covered by a test/quiz/assessment, a review session during the support class, plus be furnished with notes from text materials and lectures.
- gifted students may receive "differentiation" in the form of more busy work to do, rather than in curriculum content, pacing, and instruction in their zone of proximal development (ZPD). The new buzzword of "depth" may often be a euphemism for busywork.

When reading research, it may be important to analyze the process as well as the results. Some may find the process constructed to give specific results. When it comes to closing gaps, many have experienced that the gaps may not be closed entirely by bringing up the growth/achievement/performance students at the bottom, but also by practicing strategies which limit the growth/achievement/performance of the students at the top.