Unstructured data can include which of the following?

Unstructured data refers to information that does not have a predefined data model or format, making it complex and often difficult to analyze directly. Comments from employee surveys or reviews exemplify unstructured data because they are typically free-form text inputs. These comments can vary greatly in length, topic, and sentiment, lacking a consistent structure or organization.

In contrast, graphs and charts of performance, formal reports and presentations, and standardized test scores are examples of structured data. These types of data are formatted and categorized in a way that makes them easily accessible and analyzable using conventional data processing methods. Structured data typically follows a specific format or schema, which allows for easier sorting, filtering, and analysis. Therefore, the choice focusing on comments from employee surveys or reviews accurately represents the characteristics of unstructured data.