Perceivable: Information and user interface components must be presentable to users in ways they can perceive.
- images had alt-text, contrast ratios were good, video had suitable audio descriptions and captioning/transcription which was accessible.

Operable: User interface components and navigation must be operable.
- Clear structure that is keyboard accessible, functionality beyond the keyboard

Understandable: Information and the operation of user interface must be understandable.
- no jargon or abbreviations, input assistance in the form of error identification, labels or instructions when content requires input.

Robust: Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
- Structured course material which can be easily parsed and used.