Students learn more effectively when they have familiarity with the content they are about to learn. When teachers link what students already know (prior knowledge) with the new concepts to be introduced, they stimulate student interest, motivation, and curiosity, and give learners a sense of purpose for learning.
To build learners' background knowledge, it is important that teachers activate students' prior knowledge as a first step. Prior knowledge can be assessed through a variety of advance organizers. Advance organizers help teachers clarify what the "big ideas" are, assess what students already know, and develop links between previous and incoming material.
Once teachers have assessed what students know about a particular concept or idea, they can then use a variety of instructional strategies to introduce the material and address the diversity of learning styles and experiences students may have.
In terms of curriculum design, thematic and interdisciplinary instruction is an effective approach to build background knowledge and help learners make connections between the various content areas. This content connection strengthens the learner's ability to comprehend concepts in more depth.
Those interested in learning more about the topic can refer to Robert Marzano' text that focuses specifically on building students' background knowledge.