C. L. Gagn? and E. J. Shoben (1997) proposed that concepts are combined via external relations and that lexical entries include information about which relations are frequent for every modifying noun. As evidence for this view, they showed that relations associated with the modifier affected the interpretation of combinations in several studies in which subjects had to decide whether the combinations were sensible. The authors evaluated the methods and stimuli used in Gagn? and Shoben's experiments and present findings suggesting that the effect of relation frequency is likely due to differences between the familiarity and plausibility of different combinations. Although relation frequency could be involved in conceptual combination, the authors concluded that better evidence is needed for this variable, controlling for other more general differences between the combinations.