Certified Forester Practice Exam

Which type of scale ranks items sequentially, such as tree crown classes?

1. Nominal scale

2. Ordinal scale

3. Interval scale

4. Ratio scale

The correct answer is: Ordinal scale

The ordinal scale is used to rank items sequentially, which makes it the appropriate choice for categorizing tree crown classes. This classification system allows foresters to order the tree crowns in terms of dominance and canopy coverage, preserving the relative position of each class without expressing the exact differences in magnitude between them. For instance, in tree crown classes, one can identify dominant, co-dominant, intermediate, and suppressed classes based on their height and light exposure, but the scale does not specify the precise numerical difference between these classes. Nominal scales categorize data without any inherent order, making them unsuitable for ranking items. Interval scales provide information about the order and the exact differences between values but lack a true zero point, which is not relevant for this sequential classification. Ratio scales, like interval scales, indicate order and exact differences, but they also include a true zero, which is not necessary for understanding the ranking of tree crown classes. Thus, the ordinal scale's focus on sequence and ranking aligns perfectly with the needs for classifying tree crown classes in forestry.