Types of Data, Chapter 1 (Section 1.2) Quiz

Objectives

• Understand the structure of a typical data set.
• Distinguish qualitative and quantitative variables.
• Identify the difference between ordinal and nominal variables.
• Differentiate between discrete and continuous variables.

Data Sets

• Data sets consist of information collected on individuals, which can include people, animals, plants, or objects.
• Variables represent characteristics of individuals; in the example, they include major, exam score, and grade.
• Data refers to the specific values obtained for each variable; for individual #1, data shows Major = Psychology, Exam score = 92, and Grade = A.

Qualitative Variables

• Qualitative variables classify individuals into categories, also known as categorical variables.
• Examples include college major and gender.
• Qualitative variables differ from quantitative variables, as they describe qualities rather than providing counts or measurements.

Quantitative Variables

• Quantitative variables indicate how much or how many of something exists.
• They are numerical and include measurements, such as height and exam scores.
• Unlike qualitative variables, quantitative variables provide a numerical basis for analysis.

Ordinal Variables

• Ordinal variables are qualitative and have categories that can be ordered naturally.
• An example is letter grades (A, B, C, D, F), which reflect a ranking based on performance.

Nominal Variables

• Nominal variables are qualitative with categories lacking any natural order.
• Gender serves as a prime example, as it classifies individuals without a ranking system.

Discrete Variables

• Discrete variables are quantitative and can be listed, even if the list is potentially infinite (e.g., all whole numbers).
• They result from counting, with possible values often being whole numbers such as 0, 1, 2, etc.

Continuous Variables

• Continuous variables are quantitative and can assume any value within a given interval.
• They are not restricted to a defined list, exemplified by height, which can take on any value (e.g., 68.1 inches, 68.1452389 inches).