DICHOTOMOUS VARIABLES

Dichotomous Variable – Types

Dichotomous Variable: A dichotomous variable is a variable that has only two possible categories or values.

Examples: Yes / No, Male / Female, Pass / Fail, Present / Absent

Types of Dichotomous Variables

1. Nominal Dichotomous Variable

• Categories are based on names or labels
• No numerical meaning
• No order or ranking

Examples (Education): Gender (Male / Female), School Type (Government / Private), Medium (English / Odia)

2. Binary (Numerical) Dichotomous Variable

• Categories are represented using numbers
• Usually coded as 0 and 1
• Very useful for statistical analysis

Examples: Pass = 1, Fail = 0 Yes = 1, No = 0 Trained = 1, Untrained = 0

3. Natural Dichotomous Variable

• Occurs naturally
• Not created by the researcher

Examples: Literate / Illiterate Alive / Dead Right-handed / Left-handed

4. Artificial (Constructed) Dichotomous Variable

• Created by the researcher
• Formed by dividing data into two groups
• Based on a cut-off point

Examples: High achievers / Low achievers Above average / Below average Trained teachers / Untrained teachers

Comparison Table

Type	Basis	Example
Nominal	Label-based	Male / Female
Binary	Numerical coding	Pass = 1, Fail = 0
Natural	Occurs naturally	Literate / Illiterate
Artificial	Researcher-made	High / Low achievers

Exam Point: Dichotomous variables are commonly analyzed using percentages, chi-square test, and logistic regression.

MCQ Line: A variable having exactly two mutually exclusive categories is called a dichotomous variable.