Glossary of Terms

Qualitative Data:

Observations or information expressed using categories (dichotomous, nominal, ordinal) rather than numerical terms. Examples include sex, survival or death, and first.

Quantified benefits:

Sufficient evidence exists or can be obtained to forecast (from the current baseline position) how much improvement/benefit should result from the changes.

Quantitative Data:

Information that can be expressed in numerical terms, counted, or compared on a scale.

Quantitative usability metrics:

An indirect assessment of the usability of a design. They can be based on users’ performance on a given task (e.g., task-completion times, success rates, number of errors) or can reflect participants’ perception of usability (e.g., satisfaction ratings).

Quasi-experimental Design:

A methodology in which research subjects are assigned to treatment and comparison groups typically through some sort of matching strategy that attempts to minimize the differences between the two groups in order to approximate random assignment.