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After This, Therefore Because of This

After This, Therefore Because of This


This activity gives students practice developing intellectual flexibility by arguing for causality running in one direction and then back in the other direction. It can help students identify assumptions of causality based on the logical fallacy "post hoc, ergo propter hoc" (after this, therefore because of this).

The activity

  1. Give the following "research findings" to student groups, and tell them that they must develop at least one logical argument for A causing B.
  2. After they have come up with one or two arguments, then tell them to develop a logical argument for B causing A.
  3. Finally, ask them if there is a third variable C that might cause A and B?

(Consider using the board or overhead to keep this process organized and clear.)


Do not give one finding to each group--instead, have all the groups work on the same finding simultaneously, then randomly choose a group or two report, then move on to the next finding. By all working on the same material, students will have a reason to listen to and discuss what other groups say during the reporting phase. This keeps the class engaged and synchronized.

Example "Research Findings"

  1. Being allowed by your parents to see R-rated movies (A) correlated with greater likelihood of kids taking up smoking (B).
  2. Having a TV set in the bedroom (A) correlated with couples having lower frequency of sexual activity (B).
  3. Adolescents' watching of professional wrestling (A) correlated with fighting during dates and elsewhere (B).
  4. Listening to certain types of sexual lyrics (A) correlated with teen sexual activity (B).
  5. Alcohol consumption (A) correlated with violent behavior (B).


In each of these cases, ask students what they think could "prove" that causality runs in one direction or another. You may need to encourage discussion by relieving students of realistic constraints--for example, tell students that for this hypothetical experiment, they can have the following:

  1. As many participants with whatever background they like.
  2. Freedom to put these participants through whatever experience (intervention) they design.
  3. The ability to measure (pre-post) whatever they like.

Tell students that you will be randomly picking a few of them to share, then give the class a few minutes to work together in pairs or groups to design their causality-identifying experiment. When you do pick students to share the experiments they came up with, ask other students for ideas on how each experiment could be made either more precise or more realistic.

(From Alan Reifman, Retrieved February 2009 from )

Framing this activity for success

We all want students to carry our teachings into their lives. Often, however, we must make our intentions very plain for students to understand that an assignment will equip them with skills and empower them, and is not an arbitrary hoop through which they must jump.

For this reason, frame each activity using these four steps:

  1. Introduce the activity by making clear the specific critical thinking skill the assignment will give them practice using. They may not understand the precise definition of the term, so provide it in writing on the board or overhead. (As a reminder, definitions are here.)
  2. Share examples of how this skill can serve them in their daily lives (e.g., guiding them to buy better products, improving their performance in other classes, advancing their career, communicating better with people they care about, better understanding their own experiences, etc.).
  3. Conduct the activity as described above, making it as active and interactive as possible. When students can talk about their thinking, that thinking moves forward. Teaching for critical thinking is teaching for active learning.
  4. Conclude the activity by reflecting back to students examples that you saw of them using the critical thinking skill effectively, and reminding them to consider the relevance of that skill in other aspects of their. Repeating the examples given in Step 2 may be appropriate, as students will have a different understanding of the skill once they have experienced the assignment.

Important: Wait Five Seconds!

Among the most useful things we as teachers can do during class discussion is shut our mouths. In an oft-cited meta-analysis of wait-time research, Tobin (1987) described findings of greater engagement and achievement when teachers waited at least three to five seconds after asking a discussion question before speaking again. Above this threshold, higher level thinking was observed and student academic performance improved. However, teachers behaving "normally" only tend to wait about one second. Students need a few moments to digest what they have recently heard, formulate their responses, and work up the courage to speak. Slow down, and more of your students will keep up with you.

Reference: Tobin, K. (1987). The role of wait time in higher cognitive level learning. Review of Educational Research, 57, 1: 69-95.