# Expectations VDA's Expectation Books are designed to facilitate data quality assurance and validation. It empowers data analysts to define and run data quality tasks using expectations, ensuring that data meets predefined criteria and adheres to specific requirements. By setting and validating expectations, analysts can instill confidence in the data, leading to more reliable and trustworthy analytical outcomes. ### How to Create Expectations Expectations are part of Workbooks within VDA . Navigate to workbooks tab and select "Expectation Book" .

Expecatation Workbook

Once selected provide a name and description for the expectation book and select a Datasource on which the expectation needs to run .A Expectation book is a collection of data expectations which can be grouped as per datasources or business use-cases .

Create a Expectation

Once a book is created click on the + button on the right bottom of the screen to create an expectation .

Expectation Detail Page

Select Templated or Custom

Create Expectation Type

Expectations are of two types * **Templated** Templated expectations are predefined criteria provided by VDA, commonly used across the data industry. These expectations cover a wide range of standard data quality checks and are frequently updated. They are stored in a public repository that auto-syncs, ensuring users always have access to the latest set of expectations. Details for [templated expectations ](/how-to-guides/data-quality/expectations.md) can be found in the next sections . * **Custom** Custom expectations, on the other hand, are criteria created by organizations to meet specific needs when no relevant templated expectation is available. These allow organizations to define their own data quality rules tailored to their unique data requirements and quality standards.Templated expectations are created using templates once selected you will be redirected to create a expectation template . If you have selected Templated, then from bottom panel select Template name Enter the details like Database, Table, column(s) and expected values

Create Expectation for Template

Expectations form will change based on the template below is an example for a template for a expectation which expects column as not null .
Enter the details like Database, Table, column(s) and expected values
Expectation will get created Now you can Preview your Expectation #### --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.vdalive.com/how-to-guides/data-quality/expectations.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.