What is Categorizing?

Categorizing (also called Clustering) in cognitive psychology refers to how we identify stimuli and group them as members of one category, similar to others in that category and different from members of other categories.

Like chunking Opens in new window, categorizing involves a reorganization of separate units of information into groups to facilitate encoding Opens in new window and retrieval Opens in new window of the information.

Categorizing usually involves the grouping of nouns or pictures of objects into semantic categories. These categories may be conceptual or taxonomic in which items of clothing are separately grouped from items of furniture.

Associative groupings may also be made in which plate, table and chair are grouped into one category, while pen, desk and lamp are grouped into another. Hierarchic, superordinance and subordinate relationships may also result in separate groupings. Each category is usually labeled to assist storage Opens in new window and retrieval.

Evidence of the use of categorizing as a mnemonic technique is usually obtained in one of two ways.

  1. In the first method, subjects are given a list of randomly ordered pictures or words where each item has been selected from one of a limited number of categories, such as clothing, fruit or furniture. After the items have been removed, the subject is asked to recall as many of the items as possible. The manner in which the subject recalls the items is analyzed to determine if the items were categorized to assist recall.
  2. Alternatively, subjects may be given both randomly and categorically sequenced lists of items for the purpose of determining whether a particular type of categorizing improves memory. An important point to emphasize is that just as an effective chunk is a subjectively perceived unit of information, a category designed to improve recall must be a familiar classification of the items to the particular learner involved.

There are developmental differences in the use of categorizing mnemonics. In one study, children in kindergarten and grades one, three and five were shown a circular array of black and white, line-drawings of objects selected from animal, furniture, vehicle and clothing categories (Moely, Olson, Halves and Flavell, 1969).

The children in grade five sorted the pictures into categories, when the experimenter left the room for two minutes, after giving the instructions that the children could move the pictures around any way they wanted to help them remember.

Children in grade three required additional assistance before they began sorting the pictures. With these children, the experiment labeled each category in the array and pointed out the corresponding members in the circular array.

Children in Kindergarten and grade one began to sort the pictures only after the experimenter actually assisted them to sort the items, labeled the categories, counted the number of pictures in each and then instructed the children that they could move the pictures around any way they wished to help them remember.

Similar results were obtained by Zinobar, Cermak, Cermak and Dickerson (1975). In their study, children in the third and fifth grades spontaneously used taxonomic categories as an encoding tool, whereas children in the second grade did not. Denney and Ziobrowski (1972) found that children in the first grade tended to cluster, if at all, according to complementary groupings, e.g., words were clustered because they shared some complementary interrelationship, such as pipe-tobacco, or baby-crib. College students, however, clustered according to conceptual similarity, such as king-ruler, or crib-bed.

Black and Rollins (1982) trained children in the first grade in the use of a taxonomic organizational strategy. The children were trained to categorize pictures of common objects such as furniture, clothes, animals and food, etc., represented by linedrawings in the Peabody Picture Vocabulary Test.

Two methods of instruction were used: explanatory– and questioning method.

Explanatory methods were designed to maximize the amount of information presented to the child, and give the trainer control over the order in which the information was presented.

The questioning approaches were designed to lead the child by direct questioning to consider ways to remember. The child was also required to develop a verbal explanation of the strategy.

Piaget (1951) believed that this method would more likely lead to successful retention and transfer since it guaranteed understanding of the strategy.

Four training groups were employed; training lasted from 10.5 to 12 minutes. In all training groups, the children were taught to place the cards into categories, but the instructions varied in each group.

  1. In the general explanation group, the examiner manipulated the cards while explaining why organization was helpful in recall. For example, “If I put cards together that are similar, such as all the animals, it will be easier to remember.”
  2. In the specific explanation group, the instructions were directed toward specific items and not toward an organizational strategy. For example, “I will put the dog next to the cat.”
  3. In the general question group, the examiner asked questions, and encouraged the child to manipulate the cards. The questions emphasized the purpose for an organizational strategy, for example, “Why do we put the animals together?” Correct answers were provided, if a child did not express them.
  4. In the specific question group, the questions were directed to specific material, for example, “Where is the dog? What was next to the cat?”

All four types of training enhanced the children’s use of organization in studying and recalling the pictures. The improvement in the use of organization was maintained for several weeks, and generalized to a new set of categories after a delay of several weeks.

There was little or no difference between the results obtained by the four types of instruction. The minor differences that did occur were in favor of the explanation over the question training strategy. Also, the general explanation and questioning strategies were superior to the corresponding specific training techniques.

  1. M. W. Eysenck (1994) Perspectives on psychology (Hove, UK: Psychology Press).
  2. David Baine, Memory and Instruction (Chunking and Categorizing P. 42-48).