Critical Thinking Questions

Jump to Critical Thinking Actions Applied to Safety

The 2019 post on Chemical Engineering has a great article on safety and on a number of critical thinking and creative thinking questions that should be asked. Socratic questioning is at the heart of critical thinking and we shall use R.W. Paul’s Six Types of Socratic Questions shown in Table 1 as a basis for our discussion.⁽²⁾ A critical aspect of process safety is “anticipating” what could go wrong in a chemical process and ensuring it won’t go wrong. We are going to use an actual life example to discuss critical thinking.

Actual Case History: A large tank containing ethylene oxide has been insulated and is out in the plant. There is uncertainty as to whether or not corrosion has taken place under the insulation. To strip of the insulation and check for corrosion would require shutting the plant down for 3 weeks. Because such a shutdown would affect the supply chain and many customers, the shutdown would be very costly, ca. 5 million dollars.
- Written in conjunction with Joel Young, BASF, Wyandotte, MI

Let’s apply R. W. Paul’s Six Types of Critical Thinking questions to this situation to help us decide whether or not to strip the insulation.

TABLE 1 R.W. PAUL’S SIX TYPES OF CRITICAL THINKING QUESTIONS (CTQS)
AND EXAMPLES

Professor Fogler’s favorite types of critical thinking questions

1. Why do you think I asked this question?
2. What information do we need to answer this question?
3. Could you explain your reasoning for making that choice?
4. Can you give me an example?
5. What is a counter argument for your suggestion?
6. What are the consequences if your assumption is false?

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Critical Thinking Actions

Jump to Critical Thinking Questions Applied to Safety

In addition to critical thinking questions discussed in AWFOS-S, Table 1, we also have Rubenfeld and Scheffer seven Critical Thinking Actions (CTAs) shown in Table 2. We will use Example 13- 2 to hypothesize the CTAs for each of type of action.⁽⁶⁾

TABLE 2 TYPES OF CRITICAL THINKING ACTIONS (CTAS) AND EXAMPLES

Types of CTA	Examples Phrases of CTA	CTA Safety Examples
1. Predicting: envisioning a plan and its consequences	• I could imagine that happening if I … • I anticipated … • I was prepared for … • I made provisions for … • I envisioned the outcome to be … • My prognosis was … • I figured the probability of … • I tried to go beyond the here and now …	I knew that if the cooling system were to fail for more than 9 minutes [cf. Example 13-2], the reaction would runaway.
2. Analyzing: separating or breaking a whole into parts to discover their nature, function, and relationships	• I dissected the situation… • I tried to reduce things to manageable units … • I detailed a schematic picture of … • I sorted things out by … • I looked for the parts that … • I looked at each piece individually …	I dissected the energy balance to find the parameters that were the most sensitive to down time and temperature increases and would cause the reaction to runaway.
3. Information seeking: searching for evidence, facts, or knowledge by identifying relevant sources and gathering objective, subjective, historical, and current data from those sources	• I made sure I had all the pieces of the picture … • I knew I needed to look up, or study … • I wondered how I could find out … • I asked myself if I knew the whole story … • I kept searching for more data … • I looked for evidence of… • I needed to have all the facts …	I looked up the heat of reaction to calculate the heat generated Qg in the reactor at the start of the reaction to see if it would be greater than the heat removed, Qr.
4. Applying standards: judging according to established personal, professional, or social rules or criteria	• I judged that according to … • I compared this situation to what I knew to be the rule … • I thought of/studied the policy for … • I knew I had to … • There are certain things you just have to account for … • I thought of the bottom line that is always … • I knew it was unethical to …	I measured the corrosion inside the reactor tubes and determined the tube wall thickness was insufficient to withstand 1,000 psi according to established standards for the pipe material.
5.Discriminating: recognizing differences and similarities among things or situations and distinguishing carefully as to category or rank	• I grouped things together … • I put things in categories … • I tried to consider what was the priority of … • I stood back and tried to see how those things were related … • I wondered if this was as important as … • I listed the discrepancies in the study and found that … • What I heard and what I saw were consistent/ inconsistent with … • This situation was different from/the same as …	I made a list of all the things that could go wrong when we restart the reaction system.
6. Transforming knowledge: changing or converting the condition, nature, form, or function of concepts among contexts	• I wondered if that would fit in this situation … • I took what I knew and asked myself if it would work … • I improved on the basics by adding … • At first I was puzzled; then I saw that there were similarities to … • I figured if this were true, then that would also be true.	I was puzzled at first because I did not understand why the reactor took so long to explode after the cooling system failed [cf. Example 13-2]. Then I calculated and determined the rate of temperature increase (dT/dt) was so small that it took a long time, 2h, to reach a point where the Arrhenius dependence dominated the heat generated term.
7. Logical reasoning: drawing inferences or conclusions that are supported in or justified by evidence	• I deduced from the information that … • I could trace my conclusion back to the data … • My diagnosis was grounded in the evidence … • I considered all the information and then inferred that … • I could justify my conclusion by … • I moved down a straight path from the initial data to the final conclusion … • I had a strong argument for … • My rationale for the conclusion was …	I justified my conclusion that the reaction would not have runaway for the increased feed charge by carrying out a number of computer simulations to show that the heat generated, Qg, was less than the heat removed, Qr, for a downtime less that 5 minutes.

Professor Fogler’s Favorite Actions

1. I envisioned the outcome would be…
2. I dissected the situation…
3. I know I had to look up or study…
4. I judged that according to…
5. I grouped things together…
6. At first I was puzzled; then I saw that there were similarities to…
7. I justified my conclusion with the evidence that…

References

• “Key Questions to Guide Effective Selection of Personal Protective Equipment.” Chemical Engineering, 20 Mar. 2019. https://www.chemengonline.com/key-questions-guide-effective-selection-personal-protective-equipment-PPE-safety-chemicalsafety/
• Paul, R. W., Critical Thinking, Foundation for Critical Thinking, Santa Rosa, CA, 1992.
• See page 58-59, Fogler, H. S., LeBlanc, S. E. and Rizzo, B. R., Strategies for Creative Problem Solving, 3rd Ed., Pearson Publishers: Boston MA, 2014.
• Rubenfeld, M. G., and B. Scheffer, Critical Thinking TACTICS for Nurses: Achieving the IOM Competencies, Second Edition, Jones & Bartlett Publishers, Sudbury, MA, 2010. *
• Fogler, H. S., Elements of Chemical Reaction Engineering, 6th Ed, Pearson Publishers: Boston MA, 2020.