Turnip Soup: Head Noun Influence on the Comprehension of Noun-Noun Combinations

Turnip Soup: Head Noun Influence on the Comprehension of Noun-Noun Combinations Phil Maguire (phil.maguire@ucd.ie) Arthur Cater (arthur.cater@ucd.ie) Department of Computer Science, University College Dublin Belfield, Dublin 4, Ireland Abstract Although previous studies of noun-noun compounding have shown that past experience of a modifier influences the comprehension of combinations involving that modifier (Gagne & Shoben, 1997; Storms & Wisniewski, in press), no similar head noun influence has been found. In this paper we describe an experiment that investigates the influence exerted independently by head nouns that are particularly suggestive of the instantiated relation. Our results indicate that when suitable head nouns are examined, they exert a similar influence on comprehension difficulty to that exerted by modifiers. Combinations with biased heads were interpreted reliably faster than those with neutral heads and the head’s strength ratio contributed significantly in predicting sensicality judgment times in a regression analysis. However, while a facilitating effect was observed for compounds using a relation highly typical of the head, no inhibiting effect was evident for relations that contradicted the head’s bias. We discuss the implications of these findings and suggest some refinements to Gagne and Shoben’s (1997) CARIN model. Keywords: Conceptual combination; noun-noun compounds; relation selection; CARIN. Introduction The combination of two words is a technique commonly adopted by speakers in order to refer to novel concepts (e.g. holiday tension, picnic bee). Although people have a well developed means of understanding these novel compounds, the associated comprehension process is not trivial, requiring many levels of understanding. Accordingly, the study of conceptual combination is important, both because it is intimately associated with the generativity and comprehension of natural language and because it is important for understanding how people represent concepts. In English, a language in which compounding is particularly productive, combinations consist of a modifier followed by a head noun. Usually, the head noun denotes the main category while the modifier implies a relevant subcategory or a modification of that set’s typical members. In this way, a cereal box is interpreted as a particular type of box, and more precisely as one which contains cereal as opposed to other types of boxes. However, in order to understand a combination like this, people first have to be able to relate the two concepts in a meaningful way. Gagne and Shoben’s (1997) Competition Among Relations In Nominals (CARIN) theory focuses primarily on the relation linking the constituent nouns in a combination. This theory maintains that there is a fixed, relatively small taxonomy of standard relations that can be used to link the modifier and head noun concepts and that people possess statistical knowledge about how often each relation has been used with a modifier concept in the past. As a result, the most available standard relation is the one most frequently used to interpret other compounds containing that same modifier. For instance, the modifier mountain is most often associated with the relation thus making the combination mountain stream easier to interpret than mountain magazine which uses the relation. The emphasis placed on the primacy of the modifier is an important feature of CARIN that distinguishes it from previous theories of conceptual combination. Gagne and Shoben (1997) provided empirical support in favor of this primacy. They found that the modifier’s relation type frequency distribution influences the ease with which a combined concept can be interpreted while that of the head does not. Subsequent studies have replicated this effect in Indonesian (Storms & Wisniewski, in press) and in French (Maguire & Cater, 2004), languages in which the order of the head and the modifier is reversed. These studies showed that combinations involving a relation used frequently with the modifier were easier to interpret than combinations involving a less frequent relation, while no effect was observed regarding the relation type distribution of the head. Although Gagne and Shoben (1997) pointed out that CARIN does not exclude a role for the head noun, the theory fails to elaborate on what form such a role might take. Despite the fact that no head influence was observed in their study, we speculated that a more sensitive experiment using carefully constructed stimuli would clarify the issue of the head’s importance. Accordingly, the focus of our study was whether, under certain conditions, the relation type distribution of the head influences the interpretation process in the same manner as the modifier. We hypothesized that such an influence would be most apparent when the head is strongly biased towards the instantiated relation, as in such cases, the required relation is particularly available. Issues of Stimulus Construction The following experiment was designed in order to determine whether the relation type distribution of the head noun influences conceptual combination when the influence of the modifier is held constant. We examined whether combinations with heads that are particularly biased towards