SLS is organized very similarly to ELS: 

• Instead of the six levels of sound patterns in ELS, SLS has seven levels of scientific themes:  How We Learn (an orientation for students to the program), Earth Science, Life Science, Physical Science, Science Processes, Technology, and Morphology
• Instead of lesson words selected for their sound patterns, the SLS lesson words and terms are selected by meaning or theme, similar to the way they would be introduced in a textbook chapter.
• SLS will include two major sequences, one for grade-level and above students and another for those who struggle.
• Like ELS, SLS lessons will teach students how to pronounce, decode, spell, define, and use a word or term in a sentence.
• Like ELS, SLS includes approximately 2,000 vocabulary words and terms in almost 250 lessons.
• Teachers will be able to track the lessons that each student completes and his or her level of mastery.

In a few ways, SLS differs from ELS:

• SLS is CEI’s first program developed to align with grade-level standards; ELS and MLS are both skills-based and are appropriate for those who are behind, regardless of grade level since they teach foundational knowledge and skills.
• Both ELS and MLS were developed to operate with a trained facilitator in a lab setting.  SLS, on the other hand, was designed to operate either in a lab or at individual computers in the back of the classroom or in other learning centers.
• CEI licenses ELS by room and stations since it is a lab product.  SLS, however, will have a site license.  The school can load it on any computer in the school, without restrictions to any certain room.