1. the human


Human short-term memory has a limited span. This is a series of experiments to determine what that span is. (You will need some other people to take part in these experiments with you - they do not need to be studying the course - try it with a group of friends.)

(a) Kim's Game

Divide into groups. Each group gathers together an assortment of objects - pens, pencils, paper-clips, books, sticky notes, etc. The stranger the object, the better! You need a large number of them - at least 12 to 15. Place them in some compact arrangement on a table, so that all items are visible. Then, swap with another group for 30 seconds only and look at their pile. Return to your table, and on your own try to write down all the items in their pile.

Compare your list with what they actually have in their pile. Compare the number of things you remembered with how the rest of your group did. Now think introspectively: what helped you remember certain things? Did you recognise things in their pile that you had in yours? Did that help? Do not pack the things away just yet.

Calculate the average score for your group. Compare that with the averages from the other group(s).

Questions: What conclusions can you draw from this experiment? What does this indicate about the capacity of short-term memory? What does it indicate that helps improve the capacity of short-term memory?

(b) "I went to market..."

In your group, one person starts off with "I went to market and I bought a fish" (or some other produce, or whatever!). The next person continues "I went to market and I bought a fish and I bought a bread roll as well". The process continues, with each person adding some item to the list each time. Keep going around the group until you cannot remember the list accurately. Make a note of the first time someone gets it wrong, and then record the number of items that you can successfully remember. Some of you will find it hard to remember more than a few, others will fare much better. Do this a few more times with different lists, and then calculate your average score, and your group's average score.

Questions: What does this tell you about short-term memory? What do you do that helps you remember? What do you estimate is the typical capacity of human short-term memory? Is this a good test for short-term memory?

(c) Improving your memory

Try experiment 1.6(a). again, using the techniques on page 39.

Has your recall ability improved? Has your group's average improved? What does this show you about memory?


open-ended experiments

Other exercises in this chapter

ex.1.1 (ans), ex.1.2 (ans), ex.1.3 (ans), ex.1.4 (tut), ex.1.5 (tut), ex.1.6 (open), ex.1.7 (open)

all exercises for this chapter