Types of Data

“Data” is not just a buzzword – it’s what keeps the businesses on the right path. It provides actionable insights that help seamlessly strategise campaigns, organise the launch of products, or try out various experiments. Whether you are a researcher, data scientist, data analyst, marketer, businessman, or come from any other profession, experimenting with raw or structured data has become critical in the current scenario.

Take the example of Amazon, a leading online retailer, that reportedly processes billions of transactions and handles petabytes of data daily. This is a prime example of how data is an integral part of businesses. Hence, one must be aware of the correct method of handling and storing them to get proper insights. Data can be categorised into two types – Qualitative data and Quantitative data.

Data is further categorised into 4 types:
1. Nominal data
2. Ordinal data
3. Discrete data
4. Continuous data

Types of Data

Data can be classified based on two aspects – qualitative and quantitative. Hence, there are 2 types of data:
1. Qualitative Data
2. Quantitative Data

Qualitative Data Type (Categorical Data)

Qualitative data represents non-numerical information. It helps us understand the “why” and “how” behind things, not just the “how much.” The nature of qualitative data is descriptive and subjective. It is grouped based on categories, hence, also known as categorical data.

Let’s understand it better through these everyday examples:

• Reading a book review tells you how someone felt about the story, not just its length.
• Talking to a friend about their trip gives you their personal experience, not just the number of miles travelled.
• Looking at photos from a party captures the atmosphere and vibe, not just the guest count.

Types of Qualitative Data

There are two types of Qualitative Data:
1. Nominal Data
2. Ordinal Data

Nominal Data

Nominal data is a type of categorical data that consists of names and labels with no nominal value or intrinsic order that represents various classes or groups. For example, let’s consider a data set of bikes and their corresponding colors. They may be red, blue, yellow, black, etc. These colors are the nominal data because they represent various categories. They are names, and there is no inherent order or numerical value associated with them.

Here are a set of additional examples for Nominal Data:

• Gender: Male and Female are nominal categories, and there is no inherent order or ranking between them.
• Eye Colour: Blue, brown, green, and hazel are nominal categories defining various eye colours without any inherent ranking.
• Blood Types: A, B, AB, and O are nominal categories representing different blood types, and there is no implied order.

Ordinal Data

Ordinal data goes a step ahead of nominal data because it brings in an ordered kind of arrangement or ranking between categories; however, at the same time, the intervals among the ranking of these categories are not definitely equal or known. Ordinal data is very useful in surveys and questionnaires, and in any research whereby measuring the degree or intensity is to be done, but the exact differences are not critical.

Below are the real-time examples of Ordinal data for better understanding:

• Satisfaction Survey: People rate how satisfied they are on a scale from 1 (Very Unsatisfied) to 5 (Very Satisfied). These rankings give an order to the degree of satisfaction, but differences between ranks may be very subjective.
• Educational Grading System: Grades range from A to F, referring to students’ performances. Though there is a clear order from superior to inferior performance, the exact score difference between the grades is not defined.
• Pain Severity in Medical Assessment: Patients describe their pain as none, mild, moderate, or severe. This ranking helps in assessing and managing patients’ pain, though it doesn’t quantify the pain.

Difference between Nominal and Ordinal Data

Feature	Nominal Data	Ordinal Data
Definition	Data is categorized based on names, labels, or categories without any inherent order.	Data is categorized with a set order or rank among the categories.
Order	No natural order or ranking of the categories.	Inherent order or ranking exists among the categories, but the intervals between the ranks are not defined.
Measurement Level	Nominal scale, which is the simplest form of data classification.	Ordinal scale, which introduces a level of hierarchy or sequencing among categories.
Quantification	Categories cannot be quantified or measured mathematically.	Categories can be ranked or ordered, but differences between ranks are not quantifiable.
Usage	Used to group and identify things without implying them in any particular order.	Used to show preference, rank, or order among options where the distance between categories is not known or is irrelevant.
Analysis	Frequency counts, mode, and chi-square tests are common analytical methods.	Median, percentile, and non-parametric tests can be used for analysis.

Quantitative Data Type

Quantitative data, on the other hand, is based on numbers and measurable attributes that lead to a clearly defined way of measurement, mainly through statistical analysis. It allows one to be able to draw a conclusion based on numbers. This type of data is crucial in different fields, such as science, finance, education, marketing, and so on, and it gives a basis for creating graphs, charts, and tables that help one understand and interpret data.

Quantitative data is typically collected through measurements or counting, and it can be subjected to all methods of statistical analysis. It has a great deal of reliability and objectiveness, as numbers do not lie, thus giving a clear, concise way to report findings.

There are several applications where the importance of quantitative data is essential. For example, in finance, analysts conduct stock performance analyses, track market trends, and make investment decisions by using quantitative data.

Types of Quantitative Data

There are two types of Quantitative Data:
1. Discrete Data
2. Continuous Data

Discrete Data

Discrete data consists of countable items that can only take specific values. This type of data is characterized by clear spaces, or “gaps,” between values, meaning it cannot take on every possible value within a range. Discrete data is often represented in whole numbers, reflecting items that can be counted as separate and distinct entities.

Key Characteristics

• Countable in a finite amount of time.
• Often represented in whole numbers.
• Utilizes counting operations for analysis.

Examples of Discrete Data

• Number of Students in a Classroom: You can count the students, and you’ll end up with a whole number, such as 30 students.
• Books on a Shelf: Each book represents a discrete unit; thus, you might count 100 books in total.
• Cars Passing Through a Toll Booth: If 500 cars pass through a toll booth in a day, that number is a discrete count of cars.
• Votes for a Candidate in an Election: Each vote is a discrete entity, so a candidate might receive 2,000 votes.

Continuous Data

Continuous data, in contrast, can take on any value within a range. This type of data represents measurements and can be infinitely divided into smaller parts, offering an exact level of precision. Continuous data is not limited to whole numbers and can include fractions and decimals to represent variations in measurements accurately.

Key Characteristics

• Measurable and can represent infinitely small divisions.
• Often involves measurement of some kind.
• Utilises operations such as addition, subtraction, and averaging for analysis.

Examples of Continuous Data

• Height of Students in a School: Height can vary continuously, with measurements like 5 feet, 3.25 inches, or 160.02 cm.
• Temperature of a Room: The temperature can be 22°C, 22.1°C, or 22.125°C, showcasing the continuous nature of this data.
• Time to Complete a Task: Whether it’s 30 minutes, 30.5 minutes, or 30.25 minutes, time is a classic example of continuous data.
• Weight of Newborns in a Hospital: Newborn weights might be recorded as 6 pounds, 3 ounces, 6.19 pounds, or 2.8 kilograms, reflecting continuous measurement.

Difference between Discrete and Continuous Data

Feature	Discrete Data	Continuous Data
Definition	Data that can only take specific, distinct values and is countable.	Data that can take any value within a range and is measurable.
Nature	Quantifiable in whole numbers; represents countable quantities.	Can include any value within intervals; represents measurements.
Representation	Often represented in bar graphs or pie charts.	Typically represented in histograms or line graphs.
Operations	Counting operations are commonly used (e.g., frequency counts).	Measurement operations are used, involving precision (e.g., averages, ranges).
Variability	Limited to finite numbers; gaps exist between values.	Infinitely divisible; no gaps between values.
Statistical Analysis	Utilizes methods suitable for nominal and ordinal data, such as mode and median.	Utilizes methods suitable for ratio and interval data, including mean, and standard deviation.

Wrapping Up

Classification of data into different types, whether qualitative to quantitative, nominal to ordinal, or discrete to continuous, is worth more than the definitions in books. It is one basic aspect of data analysis that influences the way pieces of information are interpreted and decisions are arrived at. Professionals should know that difference to be able to fully realise the potential of data in yielding insights, driving innovations, and making informed decisions across a multiplicity of fields. As we continue on this tide through a data-driven world, it will be very important, if not very, very important, to understand this data classification as the very under-girding of all future triumphing research strategies and technological success.