I tried that with my students, and all of them said that it was easier to remember the 12 words in experiment 2.
WHY?
We talked about our short term memory being limited to about seven pieces of information each time previously. Once you organize the many pieces of information into groups, you now have 3 groups of 4 words each. It's easier for your short term memory to absorb the 3 groups, or the 4 words in each group than the entire 12 words.
In this Organizing and Memorizing series, we will be looking at organizing some pieces of information in some of the chapters, so that they will be easier to memorize.
Stay tuned!