Peer-reviewed research
Metrics for Text Entry Research: An Evaluation of MSD and KSPC, and a New Unified Error Metric
R. William Soukoreff and I. Scott MacKenzie, Proceedings of the ACM Conference on Human Factors in Computing Systems (CHI 2003), pp. 113-120, 2003
Read the originalRead on October 16, 2026
- What it is
- Two researchers examine the two error statistics then used in text entry studies, the minimum string distance (MSD) error rate and keystrokes per character (KSPC). They identify weaknesses in both and propose an error analysis that uses the presented text, the keystrokes and the transcribed text together.
- How much weight it carries
- Peer-reviewed CHI paper by two leading text entry researchers, read from the authors' own copy of the abstract and text. It is a methods paper, so it describes how errors should be counted rather than measuring typists.
Facts taken from this source
- A 2003 CHI paper found shortcomings in the two error statistics then used in text entry research, the MSD error rate and KSPC.
“We describe and identify shortcomings in two statistics recently introduced to measure accuracy in text entry evaluations: the minimum string distance (MSD) error rate and keystrokes per character (KSPC).” (Abstract)
- The 2003 error framework analyzes the presented text, the keystrokes and the transcribed text together.
“It combines the analysis of the presented text, input stream (keystrokes), and transcribed text.” (Abstract)