This document discusses three major types of educational research: descriptive, correlational, and experimental. Descriptive research attempts to describe current conditions without changing variables. Correlational research identifies relationships between variables without proving causation. Experimental research demonstrates causal relationships by implementing changes and using control and experimental groups with random assignment. The example given is of a teacher testing a new computerized math program with half her class, using pre- and post-tests to determine if it made a difference in achievement.