Alternative Text That Actually Informs: A Guide for STEM Instructors

In STEM fields—Science, Technology, Engineering, and Mathematics—visuals are not just decorative; they are data. A chart, a diagram of a cell, or a mathematical formula is the core of the instruction. Therefore, writing "alt-text" for STEM requires a different approach than describing a stock photo. It requires technical precision.

The Goal: Functional Equivalency

The purpose of alt-text is to provide a "functional equivalent." A student who cannot see the image should receive the exact same educational value as a student who can.

1. Charts and Graphs

Don't just describe what the graph looks like (e.g., "A bar chart with blue lines"). Describe what the graph *proves*.

• Bad Alt-Text: "Line graph showing temperature over time."
• Good Alt-Text: "Line graph showing a steady increase in global temperature from 1880 to 2020, with a sharp spike of 1.2 degrees occurring after 1980."

2. Complex Diagrams

For diagrams like the Krebs cycle or a circuit board, alt-text can become very long. If the description exceeds two sentences, use a "Long Description."

• The Tip: Provide a brief summary in the alt-text field and a full textual description in the main body of the document or a linked appendix.

3. Mathematical Equations

While screen readers are getting better at reading MathML, many embedded equations are still just images.

• The Rule: Write out the equation in plain text or LaTeX in the alt-text field. For example: "The quadratic formula: x equals negative b, plus or minus the square root of..."

Simplifying STEM Compliance

Inkable Docs helps STEM instructors identify every image that lacks a description. It also provides a dedicated interface for adding alt-text and identifying decorative elements, ensuring that even the most technical research papers are fully accessible.