Critical Chunk, Physical Length, and Number of Words Per Chunk in Programmed Instruction.

Post test performances on chunks which were either required or not required within the program revealed that both high and low short-term memory Ss did better (p < .001) with required chunks. The scores on the required response chunks were reanalyzed in terms of long, medium, and short information frames and found to be insignifi cant, although low Ss had poorer scores (p < .05) and showed signs of overloading. The conclusion drawn was that required-response chunks and not physical length of frames determines difficulty level of programmed in struction. A further analysis of the required-response chunks revealed that the number of words in a chunk did not affect performances. The implication of the study: identifying and matching the chunks necessary to respond correctly within a step of the program with a S's short-term memory can result in maximal learning. THE CHUNKING method of determining ap propriateness of steps in programmed instruc tion for high and low short-term memory Ss was previously investigated by this author (4). It was hypothesized that maximal achievement would result by matching the number of response chunks in a question frame with the number of chunks of the S's short-term memory. The find ings of this earlier study strongly supported the hypothesis. Performances on immediate and 2 day delayed posttests were poorest at the 1, 2, and 21 levels and best at 7 and 14 for both high and low short-term memory Ss. The data fur ther indicated that the low Ss would benefit most from the 7 level. An understanding of several concepts contained in the earlier study is essential to the present investigation and these, therefore, require elaboration. These concepts include the chunk, step size, and short-term memory. Miller's (8) chunking concept implies that people have a fixed memory capacity, a capacity which can be measured after a single exposure to verbal materials. The chunk itself, according to Deese and H?lse (1), may be one word or more than one word, provided these words have sufficient internal