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Validation of data collection

In today's data-driven world, accurate information is integral for the success of any business or research project. Using inaccurate, messy, or invalid data can cost time and money, leading to less insightful business decisions. This is where data validation comes into play.

Data validation ensures that the data collected and stored is accurate, complete, and consistent. It helps identify any errors or discrepancies in the collected data that may have occurred during the data collection process. This is important because using incorrect data can have severe consequences, such as skewed business decisions, poor forecasting, and reduced credibility of research findings.

In this article, we will discuss the importance of data validation, its different types, and how to perform it. We will explore the techniques used in data validation. By the end of this article, you will have a clear understanding of data validation and be able to perform validation checks on your own data.

What is data validation?

Data validation is a form of data cleansing that involves checking the accuracy and quality of data before using, importing, or processing data. The goal of data validation is to ensure that the data is high quality, free from errors, and fit for the intended use. The process involves reviewing the collected data for completeness, consistency, and accuracy to identify any errors or discrepancies.

Several types of data validation can be applied depending on destination constraints or objectives. Some common types include range checks, consistency checks, and logical checks. Range checks ensure that the values are within the expected range, while consistency checks ensure that the data is consistent across different variables. Logical checks validate the relationships between different data points to ensure they are logically sound. Other types of data validation include uniqueness checks, which ensure that each record is unique, and format checks, which ensure that the data is in the expected format.

Various data validation methods can be used to validate data points collected from respondents using a questionnaire. In addition, data validation tools like Excel can be used to perform validation checks on data values to ensure data integrity.

Data validation is essential to data quality and accuracy. By performing data validation checks, you can be sure that the data being used is of high quality and reliable. This is particularly important in decision making, where the quality of data can have a significant impact on the validity and trust in the decisions made.

Data validation is a crucial data management process that ensures the dataset collected from various data sources is of high-quality and free from errors. The end goal of the data validation process is to create a consistent, accurate, and complete dataset that is protected from data loss or errors during its life cycle.

Why is validating data important?

By validating data, businesses can gain insights into market trends, customer behavior, and product performance. This information can be used to improve decision making in marketing, product, and business decisions, leading to increased efficiency, more accurate insights, and greater revenue and profits.

Data validation also ensures that data is secure, reducing the risk of data breaches and leaks. It can save businesses time and money by reducing the need for manual data cleaning before loading data into the data warehouse. Data validation also ensures data uniqueness, reducing the time-consuming and expensive process of manual data cleaning.

Data validation is an essential workflow for businesses that rely on data to drive decision making. It ensures that data is consistent, accurate, complete, and fit for the intended use. By performing validation checks and using machine learning techniques, businesses can create a high-quality dataset that meets the overall business requirements and leads to improved business decisions.

When is data validation performed?

Data validation is typically performed at two stages: before the ETL process in data warehousing and after the information is collected.

Before the ETL process, data validation is performed to identify any potential issues with the data before it is loaded into the data warehouse. This ensures that the data is clean and consistent, making it easier to analyze. It helps to identify missing data, data format issues, and incorrect data types.

After data is collected, data validation is performed to identify and resolve any issues with the data. This allows analysts to get more accurate insights into the data, leading to more informed decision making. Common validation checks include uniqueness checks, range checks, and logical checks.

By performing data validation before ETL and after data collection, businesses can ensure that their data is clean and accurate, leading to better insights and decision making.

Types of data validation

There are multiple types of data validation checks. The right checks depend on the type of data being validated and the specific requirements of the project. By using one or more of these data validation checks, organizations can ensure the quality and accuracy of their data, leading to more accurate insights and informed business decisions.

Here are some of the most common types of data validation checks:

Data type check

A data type check verifies that data entered into a field is of the correct data type, such as a number, date, or text. For example, in a database containing customer information, the data type for the "Age" field would be a number. A data type check would ensure that the data entered in this field is a number and not text.

Code check

A code check ensures that the codes used in the data are valid and conform to specific standards. For example, a code check can verify that country codes conform to ISO standards or that currency codes are correctly formatted.

Range check

A range check verifies that data falls within an acceptable range of values. For instance, if a database contains the age of customers, a range check can ensure that all ages are within a specific range such as 18 to 100 years.

Format check

A format check ensures that data is entered in the correct format. For example, a format check can verify that phone numbers are correctly formatted, including the correct number of digits, dashes, or parentheses.

Null values check

A null values check verifies that data is not missing in mandatory fields. For instance, if a database contains customer information, the "Name" field cannot be left blank. A null values check would flag any missing data in mandatory fields.

Consistency check

A consistency check compares data across multiple fields or tables to ensure that they are consistent. For example, in a database containing customer information, a consistency check can verify that the same customer ID does not have different addresses or phone numbers across different tables.

Uniqueness check

A uniqueness check ensures that each record is unique and not duplicated. For example, in a database containing customer information, a uniqueness check would verify that no two customers share the same ID or email address.

How to perform data validation

Step 1: Use a Data Sample

Using a data sample is a good way to make the validation process more manageable. The sample should contain enough data to be representative of the entire dataset but small enough to be easily validated. This step is also useful for identifying any potential issues with the data before moving on to the full dataset.

Step 2: Apply Data Validation Checks

This step involves applying one or more data validation checks. The checks applied will depend on the type of data being validated and the specific requirements of the project. Some of the common checks include data type checks, code checks, range checks, format checks, null values checks, consistency checks, and uniqueness checks.

Step 3: Check Against the Schema

In this step, the source data is matched against the destination schema. This is important because it ensures that the data meets the requirements of the project and can be integrated into the larger dataset. The schema should be well-defined and clearly documented to ensure that the data is properly structured.

By following these steps, you can ensure that your data is validated and of high quality, complete, and accurate. This is essential for making informed business decisions and avoiding costly mistakes.

Data validation challenges

Outdated data

One of the challenges of data validation is dealing with outdated data. When data is stored in silos, it becomes difficult to validate it against current source information. In such cases, researchers have to spend time searching for updated data, leading to delays and increased costs.

Risk of errors

Manual data validation processes increase the risk of errors. Human errors such as typos, incorrect entries, and missing data can lead to inaccurate results. Such errors can result in bad decisions and negative impacts on the business.


Data validation can be time-consuming, especially when dealing with large datasets. Manually checking every record for accuracy and consistency can take a significant amount of time, leading to project delays and increased costs.

Lack of understanding

Another challenge is the lack of understanding of data management. Many businesses lack an in-house expert who properly understands data management. As a result, there may be outdated or inaccurate data, which makes it difficult to meet data validation requirements. Businesses may need to invest in training or hiring an expert in data management to avoid such issues.

Next steps

Data validation is an essential process for ensuring the accuracy and quality of data before it is used or processed. By validating data, businesses can avoid costly errors, gain more accurate insights, improve efficiency, and increase data security.

We have covered the different types of data validation, including data type check, code check, range check, format check, null values check, consistency check, and uniqueness check. Additionally, we have discussed the steps involved in performing data validation, such as using a data sample, applying one or more data validation checks, and checking against the schema.

However, data validation is not without its challenges, such as dealing with outdated data, manual errors, time constraints, and a lack of understanding of data management.

If you want to learn more about data collection and management, be sure to explore other relevant sections of the Data Collection Learning Center, such as Data collection best practices, Methods of data collection, and History of data collection. You can also visit the ETL and Customer Data Learning Centers for further insights and resources.

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