Which of the following defines how data fields are structured?

The concept of how data fields are structured pertains to the organization and arrangement of information within a data file. The option referring to columns in a data file captures this idea accurately because each column represents a specific data field, such as names, dates, or numerical values, with each field providing a discrete piece of information for the records contained in the rows.

In essence, the columns define the attributes of the data being collected, and they determine how each piece of data can be interpreted and processed. This structure is crucial for ensuring that the data can be analyzed correctly and consistently since each column corresponds to a different variable or characteristic of the dataset.

On the other hand, the other options address different aspects of data handling. Rows in a data file represent individual records or entries, not the structure of the data fields themselves. Tables summarizing findings provide an overview of results but do not define how the underlying data is structured, while textual summaries of responses may offer qualitative insights but lack the formal organization that the columns represent. Thus, understanding that columns represent the structured format of data fields is fundamental for effective data analysis and interpretation.