Accessible subscript transcription rules: math-code single elements, text-code multi-letter labels, unstack stacked subscripts¶

Strategy · All strategies
Evidence · 1 claim (1 for) · 1 study (1 design), q2 · 0 of 1 report an effect size · 1 claim rests on one study

Description¶

The v6m system instructions encode subscript elements semantically: bare numbers, single symbols, and single letters are coded as math so a screen reader reads them separately, while multi-letter labels are coded as text so they are read as words. The instructions state that "All subscript elements consisting of multi-letter labels are coded as text, so that they will be read out as words rather than as individual letters". Subscripts are transcribed in board-written order without artificially injected commas, and vertically stacked subscripts are identified and rearranged into unstacked configurations, which are more robust and simpler for screen readers.

Design Implications¶

Context¶

Requirements¶

• A screen reader up to spec for reading distinct subscript elements separately
• System instructions enforcing the math/text coding distinction

Constraints¶

• Adjacent bare-number subscripts are not semantically separated, since comma injection would violate notation standards such as Miller indices or change meaning for tensor subscripts; users can set modern screen readers to read successive numeric subscripts digit by digit

Target Learners¶

• blind and low-vision students reading math-accessible PDFs with screen readers

Target Learning Goals¶

• accurate auditory reconstruction of multi-subscript mathematical notation

Claims¶

• The v6m subscript framework robustly transcribed a wide range of board-written subscript configurations, with stacked-subscript unstacking less reliable [+W]

Related Strategies¶

• Inject LaTeX transcriptions of pointed-to math in place of ambiguous verbal references

Examples¶

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Key Sources¶

• Looney, C. W., & Duston, C. L. (2026). Using Gemini and LuaLaTeX to transcribe physics videos into PDF/UA-2 and ISO 32005 math-accessible PDFs. https://arxiv.org/abs/2608.20733. doi:10.48550/arxiv.2608.20733