Fact · Typing and writing speed
0.73correlation coefficient (r)
Across the online typists, the share of keystrokes typed with rollover correlated with typing speed at r = 0.73, a high correlation.
Checked against its source on October 16, 2026
In the source's own words
“Rollover ratio is found to have a high correlation with performance (r = 0.73, p < 0.001).”
Observations on Typing from 136 Million Keystrokes, Vivek Dhakal et al., CHI 2018, ACM Conference on Human Factors in Computing Systems, 2018, Results, Rollover Behaviour.
Open the original (DOI 10.1145/3173574.3174220)- What it measures
- The rollover ratio is the number of keystrokes typed while the previous key was still held down, divided by all keystrokes.
- What it does not show
- A correlation across people; it does not say how much faster any one person would become.