Jonah Bossewitch	Prof. Johnson-Laird

Cog 200	11/5/93

Problem 2: Memory for words

The experiment. Professor Johnson-Laird announced to his class that he would be reading them a list of words, and that they should make a tick on a piece of paper for every word that is a food. He then read to the class 64 words in the order shown in table 1. After finishing the list, he informed us that the stuff about counting how many foods were mentioned was a bluff, and what he really wanted from each of us was a list of the words we remembered him reading. Lists from 23 students were collected and the data we received to interpret this experiment are displayed in table 1.

Hypothesis. The data indicates that the average number of words remembered by each individual was 13 (table 1). Our hypothesis concerning the relative memorability of words must explain why a given individual remembered those 13 or so words and not 13 or so other words. Since 13 is greater than Miller's magic number 7 + 2, a hypothesis concerning how words are chunked together is also necessary in understanding which words were recalled. We were not given the data on which words were remembered by individuals so such a hypothesis would be mere speculation. Words could be chunked based on meaning, (synonyms, antonyms) sound, (similar sounding) size, (same number of syllables) or something else. Analyzing the appropriate data from this experiment might suggest a more conclusive hypothesis. Further experiments might include testing how many words on average are remembered from a list of 64 words if the words are more/less closely related to each other based on whatever chunking criterion you are testing. You could also add words to this list that do/don't relate to the words already on the list and see if it effects the number of words remembered.

It is difficult to determine from the data what caused some words to be remembered more than others. Some of the possible reasons a given word might have been remembered by a given person include word frequency, (I am more/less likely to remember an uncommon word) word pronunciation, (a funny British accent, stress) and humor (a professor saying "spittoon"). It is also important to distinguish between experiments in which the subjects are told that they will be asked to recall something, from those in which the subjects are not. In our experiment we were not told we would need to recall the words, but we were asked to count the foods on the list. Depending on the senses interpreted for each word about half of the words had something to do with food (table 2). Due to such a large percentage of words having to do with food it is unclear whether people recalled particular words based on the instruction given by the experimenter. The food words are well distributed over the frequencies of words remembered. The experiment could be repeated asking people to count the number of words that belong to a category that has fewer words in it than food, such as things that are used in construction. This could be contrasted with an experiment where the subjects are asked to count all of the words beginning with the letter "c" to determine more conclusively whether the instructions affect what words are recalled.

Finally, we need to explain how people can recall words that they didn't hear. It is unclear whether people heard the words incorrectly to start with and then recalled them "correctly" or whether people heard them correctly and reconstructed them incorrectly. All of the false positives sound like one of the positive words (table 3). Some of the false positives (pear, spoon) also have a semantic relationship with positive words (apple, knife/fork). Experiments that check to see if the word was correctly heard, and analysis of the frequency of the reconstructed word versus the positive word that it sounds like might shed some light on this issue.

This experiment had too many independent variables for it to suggest much beyond future lines of inquiry. Therefore it is difficult to predict the outcome of any of the experiments suggested above based on this study. One thing that is clear is that recall of words involves more than pure memory recall of meaningless items (like a bunch of numbers). If we had been read a list of 64 unique numbers I doubt that the average number of numbers remembered would have been above 7 + 2. It is difficult to predict from this data which 7 numbers it would have been. Even in the instance of "meaningless" numbers stress, accent, associations (address, lucky number) might also influence which numbers are remembered. This experiment raises far more questions than it answers.