The Two Types of Knowledge in the World A Wealth of Common Sense

Short version: There are really only two kinds of knowledge most of us juggle every daywhat you can write down and what you can only learn by doing. The first fits in books, wikis, and search bars. The second lives in your fingertips, your gut, and that eyebrow raise your grandma gives you when you’re about to make a bad decision. Let’s unpack bothwithout turning your brain into a filing cabinetand show how they dance together to make work (and life) smarter, faster, and a lot more humane.

What We Really Mean by “Two Types of Knowledge”

1) Explicit knowledge: the know-what

Explicit knowledge is the stuff you can codify: formulas, checklists, standard operating procedures, recipes, and “how to reset the Wi-Fi in three steps.” It’s easy to store, version, and sharethink manuals, PDFs, and that surprisingly helpful team wiki page last edited in 2019. In philosophy, this sits close to “knowing that,” i.e., propositional facts you can state and verify.

2) Tacit knowledge: the know-how

Tacit knowledge is personal, experience-rich, and maddeningly hard to write down. It’s how a chef “just knows” the steak has one more minute, how a nurse spots early trouble before the monitor does, or how you can ride a bike even if you forgot the physics. In management and cognitive science, this is often contrasted with explicit knowledge; it’s practical, context-dependent, and often shared best through apprenticeship, storytelling, and joint problem-solving.

If you prefer a tidy label pair: explicit is “know-what,” tacit is “know-how.” Both are indispensable. Fail to capture explicit knowledge and you reinvent wheels. Ignore tacit knowledge and you get wheels no one can drive.

Why We Keep Confusing Common Sense with Expertise

Humans run on two complementary mental engines. “System 1” is fast, intuitive, and automaticgreat for catching a falling mug or sensing a meeting has gone off the rails. “System 2” is slower and analyticalgreat for taxes, spreadsheet audits, or deciding if that “urgent” email is actually urgent. Relying only on System 1 can invite predictable errors (hello, cognitive biases), and living only in System 2 can make you miss the obvious. Real-world judgment blends the two.

Common sensewhat most people deem sound everyday judgmentsits closer to the tacit side. It’s useful, but it’s not infallible; heuristics are shortcuts, not guarantees. That’s why the smartest operators “trust, but verify”: they pair instincts with explicit checks, like a pilot’s pre-flight list or a product team’s launch criteria.

How Knowledge Actually Moves: The SECI Spiral (No, It’s Not a New Yoga Pose)

Organizations that innovate continuously don’t treat tacit and explicit knowledge as separate planetsthey convert one into the other in a loop: Socialization (tacit-to-tacit: shadowing, communities), Externalization (tacit-to-explicit: write it down, diagram it), Combination (explicit-to-explicit: connect datasets, synthesize docs), and Internalization (explicit-to-tacit: practice until it becomes second nature). This is the classic SECI model from knowledge-creation research, and it’s still a practical map for modern teams.

Street Smarts vs. Book Smarts: The Clickbait Framing We Should Retire

“Street smarts” (tacit) and “book smarts” (explicit) aren’t enemies. The kids who thrive aren’t forced to choose; they learn to translate one into the other: turning lived experience into hypotheses, and turning formal concepts into actionable habits. Even in education research and practice, there’s a recognition that both forms deserve respectand that bridging them helps students move from survival strategies to academic success.

Everyday Examples: How the Two Types Show Up at Work

Product & design

Explicit: your team’s design system, accessibility checklist, and release notes. Tacit: the senior designer’s “taste” for when a layout just breathes right, or a PM’s sense that a feature has a hidden adoption cliff. Together: you use the system to move fast, then run live sessions to sharpen intuition about where users stumble.

Operations & safety

Explicit: SOPs, incident runbooks, compliance docs. Tacit: operators’ embodied sense for subtle anomalies (“the pump sounds tired”). Together: document the fixes, but also pair rookies with veterans until the “ear” becomes muscle memory.

Sales & negotiation

Explicit: pricing tables, ROI calculators, legal clauses. Tacit: knowing when to pause, read the room, and ask a question that resets the conversation. Together: use the playbook, then review call recordings to expose the micro-moves the playbook can’t capture.

How to Grow Explicit Knowledge (Without Putting Everyone to Sleep)

1. Create a single source of truth: A searchable wiki beats scattered PDFs. Appoint owners for key pages and set review cadences.
2. Write for humans: Plain-language guidance from U.S. health agencies is surprisingly transferable: lead with the most important message, chunk content with headings, and cut jargon. Your readers should “get it” on the first pass.
3. Adopt a checklist culture: Checklists don’t insult expertise; they defend it from memory’s limits. Keep them short, action-oriented, and placed where work actually happens.
4. Codify after practice: Don’t write a 30-page SOP before you’ve run the process a few times. Capture what worked, what failed, and the exceptions you saw in the wild.

How to Grow Tacit Knowledge (Without Hoping for Magic)

1. Shadowing and pair-work: Newcomers absorb more in two days of joint work than two weeks of reading. Pair engineers, pair analysts, pair facilitators.
2. Story banks: Collect brief, real cases of “what we tried and why.” Stories are portable tacit lessons: context, choice, consequence.
3. Communities of practice: Give disciplines time and a ritual (brown bags, demos, post-mortems) to trade patterns and anti-patterns. Knowledge transfer is a social sport, not just a document dump.
4. Make tacit explicitselectively: When you notice repeated questions, pull out the repeatable essence and write it down. U.S. agencies even advise leaders to “make tacit knowledge explicit” in team practicesgreat advice outside government, too.

Turning Common Sense into Clear Communication

Common sense that only lives in heads doesn’t scale. Taking a cue from public-health communicators, make your guidance short, concrete, and findable. Use headings, front-load the most important message, and test drafts with real readers. The CDC’s Clear Communication Index and NIH’s plain-language resources show that clarity isn’t dumbing downit’s respecting your audience’s time.

Bonus: in the U.S., the Plain Writing Act pushes federal agencies toward plain language. You don’t need a law to do the same in your org; you just need a style guide and a little stubbornness.

How the Two Types of Knowledge Power Better Decisions

When teams treat explicit knowledge as the “guardrails” and tacit knowledge as the “steering,” they avoid two classic failure modes. The first is overconfidence in gut feel (those System-1 shortcuts that skip needed analysis). The second is analysis paralysis (those System-2 rabbit holes that miss the moment). Train both: teach people the models and the movesand give them reps until the models become moves.

Playbook: Simple Workflows That Combine Both Types

The 5-15-5 loop

Five minutes to recall a relevant story (“last time we shipped this, what surprised us?”). Fifteen minutes to check the explicit guardrails (definition of done, risk checklist, launch criteria). Five minutes to commit to a small experiment and a review time. Repeat. Over time, your stories get sharper and your guardrails smarter.

The “record, reveal, reduce” method

Record a routine as you do it (screen capture + narration). Reveal the hidden decision points in a transcript (“here’s why I chose path B”). Reduce the footage into a one-pager or flowchart. You’ve transformed tacit to explicit without losing the heart of it.

Mentor office hours + micro-wikis

Set weekly office hours for domain mentors and route the most frequent Q&A into a “micro-wiki” page. Limit each page to one screen’s worth of text. People will actually read it.

Frequently Asked (but Rarely Written Down) Questions

“Isn’t common sense subjective?”

Partly! But subjective doesn’t mean useless. System-1 intuition is a feature of human cognition; it just needs System-2 calibration and occasional debiasing.

“How do we know what should be codified?”

If a decision repeats, costs money when done wrong, or requires cross-team coordinationcodify it. If a decision is rare, high-context, and relies on pattern recognitioncoach it and capture stories around it. Mature orgs do both and iterate.

“Will plain language water down our expertise?”

Nope. U.S. health-communication research consistently shows plain language increases comprehension and action without sacrificing accuracy. Jargon can make experts look smart; clarity makes everyone be smart.

Conclusion

At the end of the day, “two types of knowledge” isn’t a rivalry; it’s a partnership. The explicit side keeps us aligned and accountable; the tacit side keeps us adaptive and wise. Build systems that let them feed each otherspiraling from conversation to codification and back againand you’ll compound a true wealth of common sense.

SEO wrap-up

• In software, I once coached a team drowning in incidents. Their runbooks were immaculate: pages of explicit steps. But juniors still froze when an alert hit at 2 a.m. The missing piece was tacit: diagnosing by “smell.” We set up “ride-alongs” where rookies joined seniors for real incidents. Post-incident, we clipped five-minute highlights, annotated the moment-to-moment choices (“we ruled out DNS because latency didn’t spike network-wide”), and distilled those into a one-page decision tree. Over three months, MTTR dropped, not because we added more steps, but because people internalized patterns. The explicit documents stayed useful, but the sense of the system finally spread.

  As a teacher, I learned that explaining a concept twice rarely beats showing it once and letting students try. When we taught hypothesis testing, we paired a clean formula sheet with a messy dataset from the school cafeteria. Students ran into outliers, missing values, and mislabeled rowsthe friction that never appears on the board. The formal steps (explicit) made sense only after they wrestled with the mess (tacit). Later, we codified “mess moments” into a short prep guide. Scores rose, yesbut more importantly, confidence rose.

  In healthcare, a nurse explained how she knew a patient was crashing five minutes before the monitor did: “His breathing changed, but not the way the machine catches.” That intuition came from thousands of encounters. The hospital responded by building a brief “tacit signals” deck30 slides with tiny cues and what to check nextpaired with simulations. The deck didn’t create intuition; it accelerated it by giving names to sensations and linking them to first actions. Senior nurses felt respected; juniors felt safer. The machine still mattered; the human mattered more.

  And then there’s writing. My early blog posts were stuffed with research citations and beautifully structured headingsexplicit craftyet they read like a tax return. The tacit shift came from hearing readers talk about where they got lost and what they repeated back to colleagues. I noticed their rhythms: short sentences around key ideas, one vivid example, a surprising turn of phrase. So I built a tiny ritual: after drafting, I’d read the piece out loud once (to catch awkwardness), then I’d ask, “What would a busy, skeptical friend underline?” That simple question pulled tacit audience knowledge into the room. Over time, I wrote fewer words and said more.

  Whether you’re cooking, coding, nursing, or narrating a story, the pattern is the same: you need both kinds of knowledge, and they amplify each other. Watch a pro, write down the essence, and practice until it’s yours. That’s the wealth of common sense everyone can bank.

  Casey Donovan

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  Tags: common sense explicit knowledge knowledge management SECI model System 1 and System 2 tacit knowledge two types of knowledge