Langacker: profile and base

An alternate strain of Fillmore's analysis can be found in the work of Ronald Langacker, who makes a distinction between the notions of profile and base. The profile is the concept symbolized by the word itself, while the base is the encyclopedic knowledge that the concept presupposes. For example, let the definition of "radius" be "a line segment that joins the center of a circle with any point on its circumference". If all we know of the concept radius is its profile, then we simply know that it is a line segment that is attached to something called the "circumference" in some greater whole called the "circle". That is to say, our understanding is fragmentary until the base concept of circle is firmly grasped.

When a single base supports a number of different profiles, then it can be called a "domain". For instance, the concept profiles of arc, center, and circumference are all in the domain of circle, because each uses the concept of circle as a base. We are then in a position to characterize the notion of a frame as being either the base of the concept profile, or (more generally) the domain that the profile is a part of.^[2]

Categorization and cognition

Membership of a graded class

A major divide in the approaches to cognitive semantics lies in the puzzle surrounding the nature of category structure. As mentioned in the previous section, semantic feature analyses fall short of accounting for the frames that categories may have. An alternative proposal would have to go beyond the minimalistic models given by classical accounts, and explain the richness of detail in meaning that language speakers attribute to categories.

Prototype theories, investigated by Eleanor Rosch, have given some reason to suppose that many natural lexical category structures are graded, i.e., they have prototypical members that are considered to be "better fit" the category than other examples. For instance, robins are generally viewed as better examples of the category "bird" than, say, penguins. If this view of category structure is the case, then categories can be understood to have central and peripheral members, and not just be evaluated in terms of members and non-members.

In a related vein, George Lakoff, following the later Ludwig Wittgenstein, noted that some categories are only connected to one another by way of family resemblances. While some classical categories may exist, i.e., which are structured by necessary and sufficient conditions, there are at least two other kinds: generative and radial.

Generative categories can be formed by taking central cases and applying certain principles to designate category membership. The principle of similarity is one example of a rule that might generate a broader category from given prototypes.

Radial categories are categories motivated by conventions, but not predictable from rules. The concept of "mother", for example, may be explained in terms of a variety of conditions that may or may not be sufficient. Those conditions may include: being married, has always been female, gave birth to the child, supplied half the child's genes, is a caregiver, is married to the genetic father, is one generation older than the child, and is the legal guardian.  Any one of the above conditions might not be met: for instance, a "single mother" does not need to be married, and a "surrogate mother" does not necessarily provide nurturance. When these aspects collectively cluster together, they form a prototypical case of what it means to be a mother, but nevertheless they fail to outline the category crisply. Variations upon the central meaning are established by convention by the community of language users.

For Lakoff, prototype effects can be explained in large part due to the effects of idealized cognitive models. That is, domains are organized with an ideal notion of the world that may or may not fit reality. For example, the word "bachelor" is commonly defined as "unmarried adult male". However, this concept has been created with a particular ideal of what a bachelor is like: an adult, uncelibate, independent, socialized, and promiscuous. Reality might either strain the expectations of the concept, or create false positives. That is, people typically want to widen the meaning of "bachelor" to include exceptions like "a sexually active seventeen-year-old who lives alone and owns his own firm" (not technically an adult but seemingly still a bachelor), and this can be considered a kind of straining of the definition. Moreover, speakers would tend to want to exclude from the concept of bachelor certain false positives, such as those adult unmarried males that don't bear much resemblance to the ideal: i.e., the Pope, or Tarzan. Prototype effects may also be explained as a function of either basic-level categorization and typicality, closeness to an ideal, or stereotyping.

So viewed, prototype theory seems to give an account of category structure. However, there are a number of criticisms of this interpretation of the data. Indeed, Rosch and Lakoff, themselves chief advocates of prototype theory, have emphasized in their later works that the findings of prototype theory do not necessarily tell us anything about category structure. Some theorists in the cognitive semantics tradition have challenged both classical and prototype accounts of category structure by proposing the dynamic construal account, where category structure is always created "on-line"—and so, that categories have no structure outside of the context of use.