Types of Variables

• Variables provide a means to explore the world by measuring its characteristics.
• A variable has different values based on its attributes.
• Variables are categorized as either categorical or numerical.

Categorical Variables

• Categorical variables, also known as qualitative variables, identify groups or categories.
• These variables usually have names or labels within a set of data.
• Biological sex and religious identity serve as examples of categorical variables.

Numerical Variables

• Numerical variables, also known as quantitative variables, represent measurable or countable data.
• Height and age are examples of numerical variables.

Discrete Variables

• A discrete variable has numerical values that do not contain decimals.
• It can only be expressed as a whole number.
• Number of employees or customers are examples of discrete variables.

Continuous Variables

• A continuous variable can take on any value within a given range or interval.
• These values do not have to be expressed as whole numbers and can contain decimals.
• Revenue, profit, and return on investment are classified as continuous variables.

Measurement Scales

• Variables become useful when they can be measured, analyzed, and compared.
• There are four measurement scales to compare variables: nominal, ordinal, interval, and ratio.

Nominal Scale

• The nominal scale is the most basic type of measurement scale.
• It is solely used on categorical variables.
• Grouping produce items into fruits and vegetables utilizes the nominal scale.

Ordinal Scale

• The ordinal scale is a ranking scale used on categorical variables.
• Values on the ordinal scale can only be compared in terms of rank or order.
• Categories assigned to each rank can not be meaningfully compared.
• A 5-star rating system for ride feedback is an example of ordinal scale.
• Smiley faces could easily be used to provide the same function.

Interval Scale

• The interval scale is used for continuous variables.
• Compares observations based on their distance from one another.
• Temperature is an example measure on an interval scale, the 10-degree difference between 22 and 32 degrees Fahrenheit is the same as the difference between 65 and 75 degrees.
• It lacks an absolute zero point, meaning zero degrees Fahrenheit does not indicate the absence of temperature or heat, but rather an arbitrary value.
• Values on the interval scale can not be meaningfully compared.

Ratio Scale

• The ratio scale is used to measure continuous variables.
• It has an absolute zero point, allowing for meaningful comparisons between values.
• Unlike the interval scale, a zero value on a ratio scale indicates the absence of what is being measured.
• As an example, something that is zero pounds is weightless.
• To solve many problems, it is important to understand how observations are measured, ranked and compared.
• Knowing what type of data you're measuring in grouping can help you understand which measurement scale to use.

Explore the different types of variables, including categorical and numerical. Learn about discrete and continuous variables and how they are used to measure characteristics. Understand the distinction between qualitative and quantitative data.