Why is this important?

Students have to make connections in order to be able to apply learning successfully. Making connections enhances one's ability to remember and makes use of knowledge and skills possible because the very act of making connections creates context and deepens understanding. Making connections also helps move information from short-term to medium-term memory and supports greater ownership of the material at hand. Therefore, it is important to use a variety of strategies to get students to make meaningful connections, thereby increasing engagement and improving retention.

You might want to start here:

• Short info-page about making meaningful connections by Michael Merickel of Oregon State University: Teaching and Learning Theory: Making Connections
• Article by K. Patricia Cross written as one of the Cross Papers -- easy overview of neuroscience still highly relevant despite its 1999 publication date: Learning is Making Connections 
• A brief animation of the types of connections we want readers of all ages to make to improve reading comprehension: YouTube video
  
  

See it in action:

• Teaching Channel's "Energy & Matter Across Science Disciplines": High School Science

• Teaching Channel's "Making Claims from Evidence": 2nd Grade Science

• Teaching Channel's  "Scientific Modeling in the Early Grades": K-2 Science

• Teaching Channel's  "Structure Learning with Essential Questions": 8th Grade Science

• Teaching Channel's  "When Am I Ever Going to Use This?": High School Math

Resources:

• ReadWriteThink's Strategy Guide for Making Connections when reading to improve comprehension
• ReadWriteThink's Teaching Student Annotation: Constructing Meaning Through Connections
• Weblog entry by Kristi Johnson Smith on how to encourage students to make connections between concepts: Making Connections Between Concepts
• Sara Briggs' How to Make Connections Like a Creative Genius