Previously, we found that: (i) many students were unable to construct representations of simple molecular structures; (ii) a majority of students fail to make the important connection between these representations and macroscopic properties of the material; and (iii) they were unable to decode the information contained in such representations. Assuming that lack of an understanding of the purpose of such representations inhibited students' meaningful learning, we have worked to address this "representation problem" explicitly in the context of a novel introductory general chemistry curriculum: Chemistry, Life, the Universe, and Everything (CLUE). CLUE includes a learning progression to help students master the relationships between molecular structure and bulk properties. Two methods were used to assess student learning: OrganicPad, a tablet-PC program that can recognize, record, and grade student free-form naturalistic structure drawings; and the Implicit Information from Lewis Structures Instrument (IILSI), a validated survey that asks students to identify the kinds of information they believe can be deduced from Lewis structures. A comparison of two statistically equivalent cohorts of students revealed that CLUE students show marked improvements (effect size, r = 0.6), over control students in their ability to construct structures. CLUE students were also significantly better at decoding the information that these structures contain. We present evidence that the improvements observed are due to the design and implementation of the specific learning progression rather than instructor effects. (Contains 4 figures.)