The most reliable way to improve critical thinking is to practise a few specific habits on purpose until they become automatic: clarify exactly what a claim says, ask what evidence supports it, name what it assumes, look for other explanations, and test your own conclusions as hard as anyone else’s. Then check yourself with questions that have right answers and explanations, so you learn from your mistakes rather than repeating them.
Practice questions are the fastest feedback loop. A free critical thinking test in the style of the Watson Glaser gives you an explanation for every answer, so you can see exactly where your reasoning went wrong.
1. Use a short checklist of questions
Critical thinking gets easier when you ask the same questions every time. Try these four on any claim that matters:
- What exactly is being claimed?
- What evidence is offered for it, and how good is that evidence?
- What does the claim take for granted?
- What else could explain the same facts?
Use them on a news article, a work email or a proposal in a meeting. At first it will feel slow. After a few weeks you will find yourself asking them without effort.
2. Practise finding the hidden assumption
Assumptions are the parts of an argument nobody states, which is why they are so often the weak point. To find one, ask: “what would have to be true for this reason to support this conclusion?”
Example. “We should switch to the new rota system, because the team in Bristol has used it for a year with no complaints.”
- The reason is that Bristol has had no complaints.
- For that to support switching, the argument assumes that a lack of complaints means the system works well. It also assumes that what works in Bristol will work for your team.
- Either assumption could be false. Bristol staff may simply not have been asked. Their working pattern may be very different.
Naming the assumption does not prove the argument wrong. It tells you what to check.
3. Separate what must be true from what is likely
Many reasoning errors come from treating a likely conclusion as a certain one. Practise sorting conclusions into three groups: those that must follow, those that probably follow, and those you cannot reach from the information given.
Example. “Every member of the finance team has completed data protection training. Priya is in the finance team. Tom works in the office next to it. All new starters must complete the training within their first month, and Sam joined the company six months ago.”
- “Priya has completed data protection training.” Must follow. She is in the team, and every member of it has completed the training.
- “Sam has completed data protection training.” Probably true. The rule says he should have, and he has been there long enough. But rules are not always followed, so it is not certain.
- “Tom has completed data protection training.” Cannot tell. Working next to the finance team is not the same as being in it, and nothing says when Tom joined.
This distinction sits at the heart of critical thinking tests, which ask you to judge some conclusions as certain and others on a scale of likelihood.
4. Look for other explanations
When two things happen together, it is tempting to assume one caused the other. Make a habit of listing at least two other explanations before accepting a cause.
Example. Offices that installed standing desks reported fewer sick days the following year. Before crediting the desks, consider whether those offices also changed something else, whether the healthiest teams were the most keen to adopt them, or whether sick days fell everywhere that year.
5. Argue the other side
Take a view you hold and write the strongest case you can against it. If you cannot make a fair case for the other side, you probably do not understand the issue as well as you think. This exercise also makes you better at spotting weak arguments, because you start to see which points really carry weight.
6. Check your own thinking for bias
Everyone tends to notice evidence that supports what they already believe, and to give less weight to evidence that does not. This is often called confirmation bias. To counter it, ask “what would change my mind?” before you look at the evidence, then look for that evidence on purpose. Other habits worth watching for include trusting the first figure you hear too much, and judging an idea by who suggested it rather than its merits.
7. Read arguments and summarise them
Choose an opinion piece, a report or a long article. Then write down, in two or three lines, its conclusion and the main reasons given for it. Note anything assumed but not stated. This builds the skill of seeing the structure of an argument, which is the first step to judging it. Our guide to what critical thinking skills are explains how analysis and evaluation fit together.
8. Use a framework
Frameworks give you a structure to fall back on when an argument is complicated. The RED model, for example, splits critical thinking into recognising assumptions, evaluating arguments and drawing conclusions. Our guide to critical thinking models and theory explains this and other models, with an example of each in use.
9. Practise with feedback
Reading about critical thinking only takes you so far. You improve fastest with questions that have a clear right answer and an explanation, because they show you exactly where your reasoning slipped. Keep a note of the questions you get wrong and why. After a few sessions, patterns usually appear, such as reading too much into a passage or missing words like “some” and “all”.
How to improve critical reasoning skills for a test
If you are preparing for a test such as the Watson Glaser, add these steps to the habits above:
- Learn the format first. Each section has its own instructions and answer options. Knowing them in advance saves time.
- Practise one question type at a time. Inference, assumptions, deduction, interpretation and argument evaluation each need a slightly different approach.
- Answer only from the passage. Tests judge you on the information given, not on what you know. Practise noticing when you bring in outside knowledge.
- Move to timed practice. Once your accuracy is good, practise under time pressure so the pace feels normal on the day.
Our guide to Watson Glaser test examples and tips works through an example of every question type.
How long does it take to improve?
It depends on where you start and how often you practise. Short, regular sessions tend to work better than occasional long ones, because the aim is to build habits rather than cram facts. Tracking your practice scores over time is the clearest way to see whether you are improving.
When you are ready to measure your progress, take a timed critical thinking practice test and compare your results across the five question types.
