This paper describes the role of analogy in science instruction and presents new research on the Teaching-With-Analogies model. After an introductory section, the paper discuses learning science meaningfully, including constructing relations, strategies for learning conceptual relations, the definition of analogy, effectiveness of analogies, and misconceptions caused by analogies. The model described in the paper began with a task analysis of 43 middle school, high school, and college textbooks to identify how the textbook authors used analogies to explain new concepts. The paper notes that the task analysis was supplemented by a study of 10 exemplary middle school science teachers. The model described in the paper provides guidelines for constructing analogies systematically and using them strategically during science instruction to explain important concepts in ways that are meaningful to students. The paper shows how exemplary teachers and authors construct effective analogies to help students build on their own relevant knowledge by activating, transferring, and applying it to new knowledge acquired from textbooks. Contains 44 references, 2 tables of data, and 4 figures illustrating aspects of various analogies. (RS)