Typography and layout for on-screen reading

How should text be set and laid out so a reader reads it fast, accurately and comfortably? The field calls this legibility, readability and accessible design.

Steps: frame · review · state of the art · position · against · baseline · bibliography

Claims

Claim	Grade	Where
45-75 characters per line is a safe measure	supported with caveat	review.md 1
Preference and speed disagree on line length	measured	review.md 1
Text sizes in the fluent range (x-height 0.2 to 2 degrees) read at full speed	measured	review.md 2
Larger type (18 pt and up) improves comprehension in a sample of 104	measured	review.md 2
Common serif and sans faces read equally fast on screen	measured	review.md 2
Dyslexia-specific fonts help	not supported	against.md
Extra letter spacing helps dyslexic children	measured, partly replicated	review.md 3
Contrast of 4.5:1 for text is a floor	convention, standard	baseline.md
Dark mode improves reading	not supported	review.md 4
Readers scan; scannable layout raises usability	measured	review.md 5
Words placed with the figure beat split placement	measured	review.md 6
Decorative figures help learning	not supported	against.md
Collapsed content is often missed	convention: one company article, below the quality bar	review.md 7