Critical Thinking

What is critical thinking?

Critical thinking always appears in lists of ‘21st century competencies’ along with creative thinking, problem-solving, and others. This is important because it is seen as a very significant set of competencies for education, employment and for being a usefully engaged citizen.

There are various definitions developed in the critical thinking literature. One critical thinking definition that is often quoted is that by Robert Ennis: ‘Critical thinking is reasonable and reflective thinking that is focused upon deciding what to believe or do’.

The significance of what constitutes ‘reasonable and reflective thinking’ is often seen as needing some unpacking and a further definition seeks to provide more detail. This is from Peter Facione: ‘Critical thinking is ‘purposeful, self-regulatory judgment which results in interpretation, analysis, evaluation, and inference, as well as explanation of evidential, conceptual, methodological, criteriological, or contextual considerations upon which that judgment is based.’

What are critical thinking skills?

Looking at the content of this expanded definition, it can be seen that critical thinking is, at one level, a set of skills focused on judging the significance of claims and reasoning:

• What might/does this claim (evidence, example) mean?
• How should I assess its significance?
• What more do I need to know?
• How can I explain it?
• How else can it be interpreted?
• What is being argued for here?
• What reasons are being used?
• What is being assumed (taken-for granted)?
• Is this a well-reasoned argument?
• What would make it strong(er) or weak(er)?

These skills of analysis, inference, interpretation, and evaluation are illustrated by critical thinking examples below. It is important to remember that the skills can be applied both to judgements made by others as well as to those that we make ourselves. This point provides a link to another feature of critical thinking. This is that in addition to the skills of thinking themselves, the critical thinker should also be ‘disposed’ to use them. These dispositions include being open- and fair-minded, being willing to reconsider, being trustful of reason, and being focused in inquiry.

What is a critical thinking test?

Critical thinking tests assess the level of a person’s critical thinking skills. Critical thinking tests vary in terms of which skills and sub-skills they include, but most assess skills of analysis, inference, and evaluation. Most use the multiple-choice question method. There are exceptions in one form or the other. The Ennis-Weir test, assesses only evaluation. It’s a free-writing test in which the test-taker evaluates, paragraph by paragraph, a given reasoned case. The California Critical Thinking Disposition Inventory (CCTDI) measures dispositions to use critical thinking skills.

How do you prepare for a critical thinking test?

Given that virtually all of the tests assess the level of someone’s critical thinking skills, you need to determine what the specific skills measured will be. Once you know what skills the critical thinking test includes, you need to do three things:

1. be clear as to what is involved in each of the skills;
2. be clear as to how they are assessed;
3. practise until the skills are sufficiently developed.

The first and second of these things to do are explained in more detail below.

>> If you like you can also take a free critical thinking test right away.

Critical thinking examples and example questions

Inference

Inference is one of the most prominent of critical thinking examples. This is because it is very much concerned with the logical relationship between claims (as reasons) and what is drawn/inferred from them (as conclusions). There are two types of inference, and critical thinking tests will normally assess both of these.

Deduction

The first type is deduction. In this, conclusions either logically follow or don’t (can’t) follow. Here is an example.

If international aid works in improving the economies of the poorest countries, then these economies will have significantly improved by now. However, the economies of the poorest countries haven’t improved significantly, so international aid doesn’t work in this way.

The accompanying question would be to decide whether the conclusion follows or not. In other words, does it follow from what comes before that ‘international aid doesn’t work in this way’?

The best approach in questions like this is to turn the various statements into A, B, and so on (and their negatives – not-A, not-B, and so on). Doing this with the first sentence of the above passage we have ‘If A (‘international aid…countries’) then B (‘these economies…by now’)’. The second sentence can be given as ‘not-A (the economies…significantly’), so not-B (‘international…way’). In this way, we have the simple form of ‘If A, then B. Not-B, so not-A’.

In this argument, the conclusion does follow (and, therefore, so too would other examples of arguments which have this structure.) What about the next one?

If the police are going to be able to reduce organised crime, then they need to infiltrate the various gangs that commit the crime. The police aren’t going to be able to reduce organised crime, so they haven’t been able to infiltrate these gangs.

The structure of this argument is ‘if A, then B. Not-A, so not-B’. The conclusion in this argument does not have to follow logically: though there is a given link between A and B, there could be other reasons why A isn’t the case (such as a lack of police resources). However, consider a revised version of the same content, such that ‘If A, then B. Not-B, so not-A’ and you will see that the conclusion does follow.

Induction

The second type of inference is induction. In this, we are not looking to see if the conclusion must logically follow, given the structure (as with deduction), but does it, at most, probably follow? Look at the next example.

The country’s economic data for the past 12 months show that the predicted economic growth of 2.8 per cent was too optimistic. It is likely, therefore, that the predicted economic growth for the next 12 months will again be incorrect.

As can be seen, this is a simple argument (A, so B). If we were asked whether the conclusion follows from the one reason given, then we cannot say with any certainty that it does or does not. We could judge the reason to be relevant to the conclusion, but certainly not adequate (unlike with the first of the deductive arguments above). One test (Watson-Glaser) offers the category of ‘insufficient data’ as an option here in response to the question of whether a given inference follows, and this would certainly fit here.

If a further reason was added, does this make the inference more justifiable?

The country’s economic data for the past 12 months show that the predicted economic growth of 2.8 per cent was too optimistic. Predictions of economic growth over the past ten years have also been too optimistic. It is likely, therefore, that the predicted economic growth for the next 12 months will again be incorrect.

As before, it is certainly relevant to the conclusion and, given the longer timescale of the evidence, one would judge that it makes the argument stronger. But it still hasn’t got the certainty of a deductive argument. But one could say that, given the new evidence, there is a higher degree of probability that the conclusion can be correctly drawn.

Analysis of arguments

In the above section on inference, we have seen how claims are used as reasons to support conclusions drawn from them. One of the skills of critical thinking is to understand how an argument is structured (in other words to be able to say which part is doing what).

The argument on economic data could have been written differently.

It is likely that the predicted economic growth for the next 12 months will again be incorrect. The country’s economic data for the past 12 months show that the predicted economic growth of 2.8 per cent was too optimistic. Predictions of economic growth over the past ten years have also been too optimistic.

This time the conclusion is given first, followed by the two reasons. This is not uncommon (and certainly not a problem). It could also be given between the two reasons.

The country’s economic data for the past 12 months show that the predicted economic growth of 2.8 per cent was too optimistic. It is likely that the predicted economic growth for the next 12 months will again be incorrect. Predictions of economic growth over the past ten years have also been too optimistic.

In questions that involve looking at the analysis of arguments, we need to be clear as to what is being argued for and what reasons are given in support of this.

Assumptions

A further aspect of analysis and inference is what are termed assumptions. These are taken-for-granted beliefs which form part of an argument without being made explicit. They form part of the argument by being an implicit reason.

This can be illustrated by looking again at the first version of the argument on economic growth.

The country’s economic data for the past 12 months show that the predicted economic growth of 2.8 per cent was too optimistic. It is likely, therefore, that the predicted economic growth for the next 12 months will again be incorrect.

As we saw, the conclusion of this argument was drawn from a relevant (but not adequate) reason. But if we look at the hidden part of the argument, we find a further reason that the author must accept though they haven’t stated it. This is that ‘The country’s economic performance during the past 12 months is a good guide to what will be its economic performance for the next 12 months.’ If the author did not accept this claim, then their conclusion does not fit with the given reason.

When we strengthened the argument by adding in a second reason (‘Predictions of economic growth over the past ten years have also been too optimistic.’), the argument now required a further but similar assumption:

The evidence of predictions of economic growth over the past ten years is a good guide to economic performance over the next 12 months.

In looking for what is assumed in an argument, we have to be sure that we’re looking for what the author must believe to be true, even though they haven’t stated it.

Evaluation

This skill takes us back to inductive reasoning, since we are looking here at the issue of the strength of reasoning. There are various ways in which this skill of evaluation is assessed in critical thinking tests.

One way is to evaluate proposed conclusions for a given passage. Here is an example.

Though the demand for gold continues to be very high (with economic uncertainty being a major cause of this, thereby leading to very high prices for it), there is evidence that the supply might begin to be limited. Though some new gold deposits are still being found, large reserves are increasingly rare, with the majority of production still happening in older mines that have been in use for decades.

Are either of these conclusions able to be drawn from this passage?
(A) The price of gold will continue to rise over the next decade.

(B) The price of gold can be an indication of the degree of economic certainty.

(A) NO: The passage gives information on both the present high price and high demand for gold. It also gives information on why future supply might be limited. Though this latter point might lead to the price currently being high, we cannot conclude that the price ‘will continue to rise over the next decade’ since there are other factors (including those that might cause the price to fall) that would need to be considered.

(B) YES: Since the passage gives the information that economic uncertainty is ‘a major cause’ of the very high demand for gold which in turn has led to ‘very high prices for it’, it follows that the price ‘can be an indication of the degree of economic certainty’. It should be noted that this is a weaker version than ‘The price of gold is an indication of the degree of economic certainty’ which would be too strong to be safely inferred.

Another way is to be asked to evaluate given responses to a question for their strength or weakness. Here is an example.

Should people who neglect their health be denied free health care?

YES: Doing this would mean that people looked after their own health.

Does this create a strong or a weak argument?

It creates a weak argument, since not all health problems are linked to people’s behaviour (for example, accidents and health problems associated with genetic factors).

NO: Many people might not have the necessary information about preventable causes of ill-health.

Does this create a strong or a weak argument?

It creates a strong argument, since it gives a very relevant reason which highlights the problem of the significance of the word ‘neglect’. If people don’t know how their behaviour links to possible ill-health, then they can’t be said to be neglecting their health.

As can be seen in these examples, assessments of the skill of evaluation focus on an understanding of the relationship between what is being argued for and what is being used in doing this. You can apply these skills not only to the above question-categories but also to those questions that ask for what would strengthen or weaken an argument.

Practising your critical thinking skills

In the above list of ‘How do you prepare for a critical thinking test?’ the third item was to ‘practise until skills are sufficiently developed’. So how do you do this?

Quite simply, you should take the skills already detailed and seek to use them in as many contexts as you can. This will include checking news items for the status of opinions given in them, using the skills to interrogate any evidence that you come across, applying the skills to your own reasoning when you’re producing a case for something (in the same way that you would apply them to others’ reasoning), considering possible explanations for evidence (beyond that which might already be given), and working out what assumptions are being made in any reasoning that you look at.

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What critical thinking tests exist?

One of the most well-used (and so most well-known) tests for critical thinking assessment is Watson-Glaser. This assesses your skills in inference (including both deduction and induction), finding assumptions, and evaluation. Given that it is so extensively used you can read more in a more elaborate article on the Watson Glaser test.

All three of GRE (Verbal Reasoning), GMAT, and SAT tests include critical thinking questions. The GMAT test has the biggest number of critical thinking question-types of the three, and includes not only the main areas that we have looked at, but also questions on definitions and analogies.

The Cornell Conditional-Reasoning Test also includes questions on definition (‘What does this term mean as used here?’) and also credibility (which is applying the skill of asking questions about the possible significance of evidence, when applied to who says what scenarios).

The Ennis-Weir test, as discussed above, is a test of skills of evaluation only.

There are various tests that fit with specific professions such as the Bar Course Aptitude Test [BCAT] (in the UK) for aspiring barristers. The UK BioMedical Admissions Test [BMAT] for those wishing to study medicine, biomedical sciences, and dentistry has half of its questions as critical thinking ones.