Objective strands and every achievement-level descriptor come from the
assessed-curriculum chapter of the IB's MYP sciences guide, pages
31–47, which reached this repository as three page-range extracts:
Grades6and7ScienceCriteria.pdf (year 1, pp. 31–34),
Sciences_Year_3_Rubrics.pdf (year 3, pp. 35–40) and
myp-sciences-rubric-year5.pdf (year 5, pp. 41–47). Every
line was re-checked against the text layer of those PDFs by
build/extract.py --verify: 12 criteria, 60 achievement bands and
192 descriptor strands match verbatim. No corrections were needed.
The guidance on each objective comes from a different
source — MYP Sciences.pdf, a subject-guide companion
manual compiled at Millbrook High School (August 2014), which reproduces the
objective descriptions. MYP objective descriptions are year-independent, so
the same guidance shows against all three years. It is verified verbatim
against that manual, but it is a secondary source and is the only text on
this page that is not from the IB chapters above.
Three wordings of the band 0 descriptor appear across the three years
— a standard “described by”, “identified by” and
(year 3 criterion A only) “indicated by” any of the descriptors
below — and year 1 criterion D band 1–2 reads “The student
is able to, with limited success:” rather than the usual lead. Both are
in the published guide and are reproduced as printed.