Practice
45 Quizzes · 11 CategoriesInteractive exercises built to sharpen how you analyse, weigh evidence, and decide.
Categories
Each category has a dedicated guide explaining the concepts and the full set of exercises.
4 exercises
4 exercises
5 exercises
4 exercises
4 exercises
4 exercises
4 exercises
4 exercises
4 exercises
4 exercises
4 exercises
The Full Set
Featured exercises from each category. Open a category for the full set.
Challenge your logical reasoning with classic and modern puzzles
Work through the famous farmer-fox-chicken-grain puzzle to build your constraint-satisfaction reasoning. You will learn to plan multiple steps ahead while keeping every constraint satisfied simultaneously. That skill transfers directly to project management, scheduling, and strategic planning.
Enter an island where every person either always tells the truth or always lies. Through these classic 'knights and knaves' puzzles, you will develop the ability to reason about what can and cannot be true given stated constraints. That skill is essential for evaluating contradictory testimonies, detecting inconsistencies in narratives, and constructing airtight arguments.
Confront puzzles that cannot be solved by straight-line logic alone. They demand that you question your assumptions, reframe the problem, and consider possibilities outside the obvious. These exercises build your ability to recognize when you are trapped in a mental frame and teach you techniques for breaking free, a skill crucial for innovation and creative problem-solving.
Engage with the precise machinery of propositional logic: conditionals, contrapositives, De Morgan's Laws, and valid inference forms. These exercises train you to distinguish between what an argument's structure guarantees and what it merely suggests. That is the foundation of mathematical reasoning, legal argumentation, computer programming, and any domain where precision of thought is non-negotiable.
Evaluate the strength and validity of arguments
Master the building blocks of deductive reasoning by dissecting real arguments into their logical skeletons. You will learn to separate an argument's structure from its content, a skill that lets you spot flawed reasoning even when the conclusion sounds right.
Develop the ability to surface the unstated beliefs that silently hold arguments together. By practicing on arguments drawn from business strategy, policy debates, and everyday reasoning, you will learn to find the invisible load-bearing walls that, if removed, cause the entire argument to collapse.
Sharpen your ability to weigh evidence like a scientist, distinguishing gold-standard research from persuasive-sounding but unreliable support. You will practice evaluating evidence from medical claims, business reports, and media stories, building the judgment to know when data actually supports a conclusion.
Tackle multi-layered arguments drawn from philosophy, technology policy, and scientific controversy, where you must simultaneously track premises, identify reasoning patterns, and weigh competing considerations. This exercise builds the judgment to evaluate arguments that resist simple categorization.
Identify common errors in reasoning
Develop a sharp eye for the most common reasoning errors hiding in everyday conversations, news headlines, and social media posts. You will practice distinguishing between arguments that merely sound convincing and those built on genuinely solid reasoning, building the foundational vocabulary needed to name and challenge flawed logic wherever you encounter it.
Sharpen your ability to spot misleading reasoning in advertising, political rhetoric, and daily conversations. These scenarios train you to ask the right questions rather than passively accepting claims that merely sound authoritative or persuasive, preparing you to navigate the constant stream of flawed arguments in modern media.
Learn to distinguish between arguments that fail because of broken logical structure and those that fail because of misleading content or irrelevant premises. This distinction is crucial because the two types require different diagnostic strategies. Formal fallacies can be detected by examining abstract structure alone, while informal fallacies require evaluating the relevance and truth of the content.
Practice dissecting real-world arguments that layer multiple fallacies together, as they typically appear in media, politics, and conversation. You will build the critical skill of identifying which flaw is most central to an argument's failure, learning to prioritize your response rather than getting lost in a tangle of interconnected errors.
Tackle sophisticated arguments where multiple fallacies interact and reinforce each other, as they do in real public discourse, corporate communications, and expert debates. You will practice untangling layered reasoning, develop strategies for responding constructively rather than just identifying errors, and learn how fallacies are deliberately combined to create arguments that are far more persuasive than any single fallacy alone.
Practice making better decisions with scenario-based exercises
Develop the ability to quantify tradeoffs, recognize hidden costs, and systematically compare alternatives instead of relying on gut reactions. These skills prevent costly oversights in career moves, major purchases, and everyday resource allocation.
Strengthen your ability to navigate morally complex situations by applying structured ethical frameworks rather than relying on intuition alone. These skills are essential for leaders, professionals, and citizens who must justify decisions affecting others' lives and well-being.
Build fluency in distinguishing risk from uncertainty, calculating expected values, and recognizing the psychological biases that warp human risk perception. These skills protect you from both reckless overconfidence and paralyzing overcaution.
Master structured decision frameworks for high-stakes choices involving multiple competing objectives, uncertain information, and diverse stakeholders. These methods turn overwhelming complexity into manageable, defensible comparisons that you can articulate to others.
Sharpen your ability to identify patterns and trends
Explore how patterns emerge in real-world data and learn to distinguish genuine regularities from coincidental sequences that trick our pattern-hungry brains.
Examine how patterns manifest in language, behavior, and historical events, and practice distinguishing structural regularities from superficial resemblances.
Tackle patterns that require deeper logical deduction, including recognizing when apparent patterns are misleading and when hidden variables drive observed regularities.
Confront sophisticated challenges in pattern evaluation, including multi-variable systems, the psychology of false pattern detection, and the boundaries of statistical reasoning.
Recognize and overcome systematic errors in thinking
Train yourself to recognize the most pervasive cognitive biases that distort everyday thinking. Through realistic scenarios spanning workplaces, hospitals, and personal relationships, you will learn to name each bias, understand its psychological roots, and apply concrete strategies to counteract it before it derails your next important decision.
Explore how cognitive biases systematically warp financial judgments, consumer choices, and risk assessments. Through scenarios drawn from investing, medicine, shopping, and organizational life, you will learn to detect the invisible forces that push decisions away from rationality and practice concrete techniques for resisting them.
Examine how the presence of others, group loyalty, social hierarchies, and cultural narratives systematically distort individual and collective reasoning. Through scenarios set in hiring committees, courtrooms, medical offices, and social media, you will learn to recognize and resist the social forces that silently override clear thinking.
Master the advanced metacognitive tools that researchers and elite decision-makers use to detect and counteract bias in real time. Through scenarios involving forecasting, strategic planning, personal finance, and intellectual discourse, you will build a practical debiasing toolkit and confront the sobering reality that knowing about bias is not the same as being immune to it.
Assess credibility of information and detect misinformation
Build a systematic toolkit for judging whether an online source deserves your trust, practicing the same checklist professional fact-checkers use every day. These skills will help you quickly separate credible health advice, news reports, and research claims from misleading content you encounter on social media, search results, and shared links.
Sharpen your ability to detect misleading statistics, manipulated visuals, and viral falsehoods by working through scenarios drawn from real-world misinformation campaigns. You will practice the same rapid-assessment techniques that professional fact-checkers use to triage dubious claims before they spread further.
Learn to recognize how framing, selection, and omission shape the news you consume, and practice techniques for cutting through editorial spin to find the underlying facts. These skills transform you from a passive news consumer into an active analyst who can read any outlet critically without falling into reflexive distrust of all media.
Master the skills needed to evaluate complex information ecosystems where bias is structural, expertise is contested, and misinformation is laundered through credible-seeming intermediaries. These techniques prepare you to critically assess think tank reports, corporate disclosures, expert commentary outside its domain, and the sophisticated influence operations that shape public discourse.
Apply the scientific method and evaluate research claims
Develop a rigorous understanding of how scientific inquiry produces reliable knowledge by evaluating hypotheses, controls, replication, and falsifiability in realistic research scenarios. You will practice distinguishing testable predictions from unfalsifiable claims, recognizing when anecdotal evidence masquerades as data, and understanding why independent replication is the ultimate arbiter of scientific truth.
Sharpen your ability to distinguish genuine causal relationships from misleading statistical associations by analyzing scenarios from epidemiology, economics, education, and public health. You will learn to identify confounding variables, reverse causation, collider bias, and ecological fallacies that routinely lead policymakers, journalists, and even researchers to draw invalid conclusions from correlational data.
Develop the skills to critically appraise scientific claims by dissecting sample sizes, placebo controls, statistical versus clinical significance, publication bias, p-hacking, and the limitations of peer review. These competencies will equip you to evaluate health news headlines, pharmaceutical marketing, and policy arguments that invoke "studies show" as their authority.
Tackle advanced challenges in experimental design by analyzing blinding procedures, operationalization decisions, ecological validity, randomization failures, and the replication crisis through detailed real-world research scenarios. You will build the ability to spot subtle methodological weaknesses that can invalidate even well-intentioned, well-funded studies and to evaluate whether a study's conclusions actually follow from its design.
Develop innovative solutions through divergent and lateral thinking
Build your capacity to generate a rich variety of ideas by studying real breakthroughs where quantity and flexibility of thought outperformed narrow expertise. You will practice the foundational techniques of divergent thinking, lateral thinking, and constraint removal that separate prolific innovators from linear problem-solvers. These skills transfer directly to any domain where novel solutions are valued over incremental improvements.
Practice redefining challenges through real cases where shifting perspective turned intractable problems into elegant solutions. You will practice reframing, first principles thinking, and design thinking through scenarios drawn from medicine, startups, manufacturing, and public policy. These exercises reveal why the way you frame a problem determines your solution space more than any amount of effort within the wrong frame.
Explore how celebrated innovations emerged from connecting ideas across distant domains, and train your ability to recognize deep structural patterns linking seemingly unrelated problems. You will practice analogical transfer, biomimicry, the SCAMPER technique, and combinatorial creativity through scenarios spanning biology, architecture, business, and technology. These exercises develop the cross-pollination instinct that research identifies as the single strongest predictor of creative output.
Grapple with the counterintuitive dynamics of complex systems where good intentions reliably produce terrible outcomes and small interventions at the right point create massive change. You will practice recognizing feedback loops, emergence, unintended consequences, and leverage points through scenarios drawn from urban planning, technology platforms, ecology, and organizational behavior. These exercises train you to see the interconnected whole that linear thinkers consistently miss.
Reason about uncertainty, risk, and statistical claims
Confront the scenarios where human intuition about probability fails most dramatically, from emergency rooms to courtrooms to casinos. These puzzles expose systematic flaws in how our brains estimate likelihood, teaching you to recognize when your gut feeling is being hijacked by cognitive shortcuts. Mastering these foundations will change how you evaluate risk in medical decisions, financial choices, and everyday life.
Develop the skills to interrogate statistical claims you encounter in news headlines, pharmaceutical ads, corporate earnings reports, and political campaigns. These exercises train you to spot the specific techniques that make misleading numbers look convincing, from axis manipulation to cherry-picked comparisons to survivorship bias. You will learn to ask the right questions before accepting any statistical claim at face value.
Master the framework that doctors, intelligence analysts, and data scientists use to update beliefs rationally when new evidence arrives. These exercises build your intuition for Bayes' theorem through scenarios involving criminal investigations, medical diagnosis, A/B testing, and geopolitical analysis. You will learn when evidence should dramatically change your mind versus when it should barely shift your confidence.
Identify the most dangerous statistical fallacies that lead to wrongful convictions, failed policies, wasted research funding, and medical harm. These advanced scenarios test whether you can spot subtle errors involving Simpson's paradox, the prosecutor's fallacy, multiple comparisons, selection bias, and expected value traps that regularly fool judges, journalists, scientists, and executives.
Draw comparisons and transfer knowledge across domains
Build foundational skills in analogical thinking by exploring how analogies work in science, everyday reasoning, and communication, and learn why even simple analogies carry hidden assumptions.
Dissect real-world arguments built on analogy, from legal precedent to policy debates, and develop rigorous criteria for evaluating when an analogy strengthens or undermines a case.
Practice the high-value skill of transferring insights across fields, from biology to business and medicine to engineering, while learning to identify when cross-domain mappings illuminate and when they distort.
Master advanced techniques for stress-testing analogies, including identifying hidden structural assumptions, measuring analogical distance, and understanding how metaphorical framing shapes thought and policy.
Audiences
Hand-picked paths for specific learners. Each page sets a study order and explains why those skills matter.
Clinical reasoning is critical thinking under time pressure. Practice the moves before you need them at the bedside.
The reasoning skills you build in high school are the foundation of everything that comes next.
The reasoning skills your professors assume but rarely teach explicitly.
Better decisions, not louder opinions, are what distinguish strong managers.
It is never too late to sharpen the skills that matter most.
Calibration
Pick exercises that match where you are now.
Perfect for those new to critical thinking. Focus on basic concepts like recognizing simple fallacies and elementary logic puzzles.
For those with some experience. More complex scenarios requiring deeper analysis and evaluation of arguments.
Challenging exercises for experienced thinkers. Complex multi-step reasoning and sophisticated argument structures.
Method
Every exercise here rests on one principle. You learn critical thinking by doing it, not by reading about it. The questions are not trivia. Each one puts a real scenario in front of you: a post making a shaky claim, a decision under uncertainty, a news story that buries its assumptions. Your job is to name what has gone wrong in the reasoning.
Three habits separate learners who improve from learners who plateau. Name the flaw in your own words before you look at the options. When two options both fit, ask which one the conclusion actually rests on. When you are wrong, read the explanation twice and work out why the wrong option looked good. That is where the reusable lesson sits.
Do not race through a category in one sitting. This skill consolidates between sessions, not during them. Three exercises today and three tomorrow beat six this morning. When a pattern keeps catching you out, pair the quiz with its Learn module.
Map of the territory
Logic puzzles and analogical reasoning train the move almost every argument depends on: noticing when a step does not follow. Fallacies and cognitive biases give you names for the most common defects, so you catch them in a second rather than in hindsight.
Argument analysis and source evaluation are about reading. You separate what a piece claims from what it supports, then judge how much the evidence can carry.
Probability & statistics and scientific reasoning cover noisy evidence: base rates, confounders, and why correlation keeps getting mistaken for causation. Decision making and creative thinking train how you choose under uncertainty and how you find new framings when every obvious option is poor. Rotate across categories. The skills reinforce each other.
FAQ
