Why was experiment 2 so much more difficult than 1? Well, there are a couple of differences. In the first experiment you really had only five categories of things to remember: money, fruits, directions, names, and colors. The number of words is much easier to handle when they can be grouped. Sometimes, this grouping will cause you to remember words that weren't there but are in the group. Also, the list was made entirely of everyday, common nouns. North and apple are words that we've used a lot in our life, so the path to remembering them is strong and easy to use. Compare this to the second experiment. The words were nothing like those in the first experiment. They were all words that weren't very common in daily life. There were twenty separate words, that couldn't easily be grouped. Since the short-term memory can really only handle about seven things at a time, five categories weren't hard, but twenty words were. These differences made experiment 2 harder.