Variable

Topic: Economic Data: Census, NSS, Surveys and Statistical Tools · NCERT: Class 11, Ch 2 "Collection of Data"; Class 11, Ch 3 "Organisation of Data"; Class 11, Ch 8 "Use of Statistical Tools"

Meaning

A variable is a quantity that takes different values in different situations. Examples are height, income, output or marks. It is usually written as X, Y or Z. A continuous variable can take any value, including fractions (height, weight). A discrete variable moves in jumps (number of students). Qualities that cannot be measured, such as gender, are called attributes.

Example

India's foodgrain output is a variable. It was 108 million tonnes in 1970-71 and 272 MT in 2016-17. Each yearly figure is one observation of that variable.

Don't confuse with

• Attribute: an attribute is a quality that cannot be measured in numbers, such as gender or religion. It is recorded only as present or absent.

Related concepts

• Primary data
• Secondary data
• Survey
• Observation
• Questionnaire
• Enumerator
• Informant
• Closed-ended question
• Open-ended question
• Leading question

Read more

• Where data come from: sources, questionnaires and survey modes