Types of rules
On an intuitive level, some concepts seem to be more difficult than others. Concepts may differ in complexity partly because of differences in the complexity of the rules that define them. Neisser and Weene (1962) classified conceptual rules according to how many logical operations they involved.
Refer to Table 23.1 for more details on rules.
Table 23.1 Five types of rules that define concepts and examples
Neisser and Weene identified three levels of difficulty defined by the number of logical operations required in each. They had inexperienced subjects learn concept at all three levels of classification. In general, the greater the logical complexity of the rule, The longer it took the subjects to learn the concept.
Subsequent experiments have found· that the initial differences in learning the different types of rule may have arisen from prior experience not from inherent differences in the difficulty of various rules. "It was also found that learning the various logical operations makes it easier to learn rules that include those operations.
Attention And Concept Formation
The way we attend to the stimuli and concepts also determine the formation of a concept. In general, attending to irrelevant attributes retard concept formation, whereas attending to relevant attributes facilitates it.
The role of attentional factors has been explained in the context of studies of the development of conceptual ability in children. In one type of quantitative conservation problem the same amount of water was poured into a taller, thinner glass from one of shorter glasses while the child looks on. If the child states that both i.e. tall and shorter glasses have the same amount of water and can justify her answer adequately, she is said to understand the concept of quantitative conservation. Most pre-school children do poorly on this type cf conservation problem because they attend only to the height of the water in the glasses. In this problem the height is an irrelevant attribute. Thus proper training helps in ignoring the irrelevant attributes and attends to relevant attributes thereby helping the child to learn cognitive conceptual abilities.
Typicality and Exemplar Variability
We saw earlier that many theorists view concept formation as a process of abstracting prototypes and learning transformation rules (prototypes are idealized representations of some class of objects or events. For Ex: Robin is a prototype to the concept of birds). Prototype views of the concept holds that prototypes of concepts include features or aspects that are characteristic -that is, typical-of members of the category rather than necessary and sufficient. No individual feature or aspect has to be present in the instance for it to count as a member of the category or concept, but the more characteristic features or aspects in instance has, the more likely it is to be regarded as a member of the category. For example chair, sofa, table are regarded as furniture more quickly. Here chair, sofa and table are prototypes of furniture. If we indeed form categories by organizing them around prototypes, we would expect that highly typical category members are learned faster than atypical members. Research has supported this view. Thus level of typicality influences the rate of learning category members. Learning category members can contribute to concept learning via both analytic and non-analytic, which are described in the previous lesson. Regardless of what type of strategy one employs, it is advantageous to learn highly typical category members first.
Degree of variability of the presented instances of a category affects how novel instances will be classified. Presenting highly similar instances ones that are low in variability may enhance the abstraction of prototypes and the recognition of common features. But it is difficult to know what the boundaries of a category are when one has seen only a few highly-similar instances. For this reason, presenting highly dispersed instances facilitates the learning of category boundaries.
Information And Concept Formation
Information value of the stimuli does influence concept formation. Some early experiments on concept formation suggested that people learn concepts more readily from positive than from relative instances since positive instances are more informative.
Theorists now believe that informational variables are fundamental determinants of concept formation. For example, prototypes are believed to be the most informative members of the categories. If you knew the prototype of a particular category, you would know a great deal about the category much more than you would understand if you knew only an atypical member.
Biological Determinants
Biological factors also influence category formation. Our innate biological structure makes us to define concepts in a similar way across cultures. Inborn tendencies do exist, which influences the formation of concepts, which is illustrated in a more detailed example as follows. Theorists once believed that people perceive colors in accord with the color categories inherent in their language. In this view, one's perception of color is determined by and relative to one's language. This position has now been shown to be incorrect. People all over the world find the same colors to be highly salient, regardless of the vast differences in how their languages divide up the color spectrum. Additionally, the color names in all languages come from a small, highly constrained set, and linguistic color categories are organized around the colors that are universally salient. So the color categories people form are not arbitrary but are determined by biological factors. This example makes it clear that biological factors play a strong role in the formation of certain concepts, which are formed uniformly across varied cultures.SUMMARY
There are numerous determinants of concept formation. The prior experience of the learner influences concept formation in several ways. Subjects who have received special training learn from negative instances as well as positive instances. Also, people who have learned several different types of conceptual rules learn new rules very quickly. Through practice, subjects may become more efficient in finding and testing relevant attributes and in learning the logical system implicit in conceptual rules. Attentional factors are important in that attending to irrelevant attributes retards concept formation, whereas attending to relevant attributes facilitates it. Concept formation is influenced strongly by informational variables. Highly typical category members are highly informative, and they learned faster than atypical less informative members of the category are. Biological factors also influence concept formation as is evident from formation of concept of colors.