1. The problem asks about the level of measurement used when employees are classified by national origin. 2. Levels of measurement describe how data is categorized and include nominal, ordinal, interval, and ratio. 3. Nominal level classifies data into distinct categories without any order or ranking. 4. Ordinal level classifies data with a meaningful order but without consistent differences between categories. 5. Interval level has ordered categories with equal intervals but no true zero. 6. Ratio level has ordered categories with equal intervals and a true zero point. 7. Since national origin is a category without inherent order or ranking, it is classified at the nominal level. 8. Therefore, the level of measurement used is **nominal**.