Which type of theory is most abstract and broad, forming the basis of a knowledge base?

• A. Grand theory.
• B. Midrange theories.
• C. Conceptual models.
• D. Evidence-based practice.

Answer: (A)

Grand theories are the most abstract and broad, shaping the overall understanding that underpins the entire knowledge base. They offer wide-ranging explanations of nursing phenomena and the relationships among broad concepts, providing the foundational assumptions that guide what is studied and how it’s interpreted. Because of their scope, they establish a high-level framework rather than focusing on specific, testable details, which is why they sit at the top of the hierarchy and inform more concrete theory work.

In contrast, midrange theories zoom in on particular phenomena or populations and are more amenable to testing and application in specific settings. Conceptual models describe relationships among concepts but are typically less formal or comprehensive than full theories. Evidence-based practice is a method for integrating research evidence into clinical decisions, not a theory.