Students walk in and I spread them around the room and ask them to clear their desks other than a pencil and a blank piece of paper.
I tell them that we are going to do a memory task and that it is not a measure of their intelligence but a measure of their memory.
I have a list of twenty words that I say pausing for a second or two between each word. The students are told that they are to remember as many as they can and then at the end they will write down as many as they can remember.
Once this is done I ask for a show of hands going through each word in order that I said it. I create a table of values of the position of the word versus the number of people that remembered it on the board. Time for students to get to work. I ask them to create a graph of position of the work versus percent of the people that remembered the word.
Here is what it would look like.