This research investigates issues surrounding early school children's use of the similarity between head and modifier terms in deriving interpretations for novel noun-noun conceptual combinations. In these experiments, 6- and 9-year-olds and adults were asked to formulate interpretations of similar and dissimilar conceptual combinations. Both children and adults were sensitive to the similarity aspect of conceptual combinations, although the children had some difficulty with the property interpretations that high-similarity combinations require. Next, we examined 40 popular children's books for the presence of noun-noun conceptual combinations. Adult participants provided interpretations for these combinations and rated the similarity of the head and modifier nouns. Results indicated that there were few high-similarity combinations and few combinations requiring property interpretations, suggesting that children have limited exposure to highly similar combinations and property interpretations. Further analysis of children's interpretations indicates that they may have difficulty in selecting and integrating properties of the modifier onto the head, a process required by property interpretations.