What type of theory is defined as facts or principles used to explain phenomena?

The selection of descriptive theory as the correct answer highlights its fundamental role in architecture and other disciplines. Descriptive theory is focused on articulating and clarifying the existing facts or principles that underpin various phenomena. It describes how things are, offering a systematic account of observations and established knowledge without necessarily suggesting changes or improvements.

This type of theory is essential in understanding phenomena because it lays the groundwork for further exploration and understanding. By presenting observed facts and principles, descriptive theory provides a foundation upon which other theoretical frameworks can build, such as prescriptive or applied theories which may suggest or implement changes based on the observations noted in descriptive accounts.

In contrast, critical theory involves examining and questioning societal structures and power dynamics, often with the aim of promoting social change, while prescriptive theory focuses on proposing methods or techniques for improvement or action. Applied theory takes established principles and applies them to real-world scenarios, building on the groundwork provided by descriptive theory. Each of these theories serves a different purpose, but descriptive theory fundamentally explains phenomena, making it pivotal to any analytical framework in architecture and beyond.