Group Activity - Identifying Trends (and their causes and effects)!

I borrowed the following group activity from page 473 of Writing in the Works (appearing in Chapter 13 - The Research Article), and I received really good feedback from my students about it. I did tweak it a little so thought I would share how I implemented it in the classroom. The students said that it really helped them understand the concept of not only a trend, but also cause and effect, and that discussing it with each other was helpful. Here it goes:

Break the students into groups of 3-4. Each group must produce four examples of contemporary trends, and each group member should contribute at least one trend idea. Then, each group must come up with two causes and two effects for each trend. I think that encouraging them to list more trends or more than two causes and effects per trend would be useful, but due to lack of time today (was I talking too much in class before this activity?), they only had ten minutes to come up with ideas. I then asked each group to share their ideas with the rest of the class, and they had chosen a spokesperson without me prompting them to do so, which seemed to work out well. The results were great: overlapping trends, trends within trends, creative and interesting trends, conflicting trends (which I pointed out would certainly need more research for proof). It was Trend City it my class today, and with all of the students contributing their own ideas as well as hearing each other's, it certainly seemed to clear up any confusion about trends and their causes and effects.