Declarative, Procedural, and Conditional Knowledge

Under any skill there are three separate jobs, and holding one of them does not give you the others. The first is knowing what the thing is and what it accomplishes. The second is running it without spending attention on the running, which is a different achievement and arrives later. The third is judging, in a situation you have not met before, that this is the move to reach for. The labels are the psychology terms — declarative, procedural, conditional — and keeping them apart is what makes them worth having: when a technique you understand completely still fails in performance, the job that is missing tells you which practice to do next.

Where the boundaries sit

Declarative knowledge is the foundation: facts, concepts, relationships — anything that can be explained — and, on this page, any step still chosen on purpose. Every other type builds on it. Content-heavy subjects lean this way almost entirely. History, biology, and theory of any kind sit here. Medicine is mixed: the facts and the diagnostic plan are declarative; the practised motor of a procedure is not.

Procedural knowledge means automatic. Driving, native-sounding pronunciation, fluent code — execution so practised it runs without thinking about the steps. The closest picture is muscle memory. It is not “knowing how” in the everyday sense. Taking disease facts, picking a diagnosis, and writing a plan is still choosing, reasoning, and lining up steps on purpose. That stretch is declarative end to end. Procedure begins only where conscious control ends. This is this vault’s cut, not a line the field drew in the same place.

The automatic kind develops slowly, and only through doing. Once it locks in, the declarative scaffolding underneath can fade. A fluent speaker who cannot state the adjective-order rule is the usual picture: the production runs, the verbal access has gone. Global Workspace and J-space is why — the skill has left the deliberate workspace. Knowledge Mastery From Recognition to Usable Knowledge grades the declarative side of the same split; the levels stay on that page.

Conditional knowledge is knowing when and why to deploy what is already held. On this page it is a subset of declarative: the when and why can be explained on demand. Scholars do not agree that it is a separate type. Strategy-instruction work treats the when-layer as something to teach explicitly. The house stance is different and narrower. Building declarative and procedural well across varied contexts, challenge types, and time pressures produces the when-layer as a by-product. It grows when context is changed on purpose. It does not grow by waiting.

What experience teaches

The theory is engaged first — notes, analogies, connections, critique — and the skill is attempted as soon as there is enough of it to discover the first mistakes. That is working understanding, then the attempt. Rapid Skill Acquisition is the pacing: not certainty, then practice. Certainty before the first attempt is impossible. Chasing it through more clarifying questions postpones the only teacher that works.

Fail fast, fail safe means finding the cheap early mistake so it is not met when the cost is concentrated. A messy session half a year out is cheap information. Finding the same hole in the last week stacks the cost into one window. Small early errors pre-empt the large late ones.

A skill may offer hundreds of possible mistakes. Any one person makes about five to seven of them. Those are the tendencies to hunt. Trying to pre-empt the whole catalogue with what-if questions overwhelms working memory and stalls the start. The start is what produces the five-to-seven.

Some tendencies leak in from another domain and are invisible from inside. A trained habit from a different skill jumps sideways and keeps firing. An observer sees the jump. The person doing it does not.

The loop after an attempt is try, reflect against the declarative model, refine, retry. Strong theory converts a failed attempt into a targeted question. Kolbs Experiential Cycle is that loop: what happened, how it felt and why, what rule that suggests, what changes next time.

Understand completely, still cannot perform

That dissociation is why the cut exists. Understanding is not performance. Knowing what to do is a small fraction of mastery. Most of the work is constructed through practice. Each job has a different best teacher: explanation for the first, the attempt for the other two. The fraction is a teaching split, not a measurement. No study prices knowing-what as a tenth of mastery.

Diagnosing the bottleneck

Suspect declarative first. Even in subjects that look procedural, the usual jam is deciding which method to use, in what order, for this situation — and that decision is declarative. A great deal can be solved without procedure if each step can be paused and decided. Pure execution is increasingly cheap to automate. The approach, strategy, and judgment layer stays expensive. That is a reason to look at the first job first, not a forecast about labour.

Someone who can finish the usual practice set and then falls apart when the same problem arrives inside a real case is missing a concept, not reps. More volume of the same set will not supply it. Interleaving for Complex Problem Solving is that diagnosis applied. The test is a messy challenge. A wrong method, a wrong order, or a broken chain of reasoning is a declarative gap. The right method done clumsily — a slipped calculation, a syntax bug, stiff prose — is a procedural gap.

Match practice to that diagnosis. Retrieval methods split along the same line. Interleaving Table is the split; this page supplies the type variable. Spaced Interleaved Retrieval is the retrieval system that takes the variable. The triad is used before the next hour of practice or the next test, not recited after it.

What is house, what is field

The house cut is a useful diagnostic, not a consensus definition. A reader who treats the three names as natural kinds will call application procedure and then pile on more drills of the same shape. The field often treats application as a mix, and treats the when/why as teachable. Both disagreements are real. The cut is still the tool this page is for: if the steps are still being chosen, the hour is declarative.

The surviving split is explanation versus attempt, not person versus experience in every domain. A coach can shape procedure by feedback, demonstration, and constraint. Mental practice can move it a little. The direction is still the same: the first job arrives from being told, and the other two are built in the doing.

The 10/90 split and the five-to-seven-of-hundreds are this system’s teaching numbers, not findings. Varied practice is the technique for the when-layer. “No dedicated techniques” and “develops for free” are too strong as absolutes. If the next hour is still chosen step by step and the practice is more drills of the same shape, the diagnosis was skipped. The check is the next messy problem: it either exposes a wrong approach, or a right approach done clumsily.

The next hour, classified

The triad is used before the next hour, not recited. An hour that can still be explained step by step is treated as declarative, even when it looks like doing. An hour that runs without the steps being chosen is procedural. An hour that changes context on purpose is how the when-layer grows. The names are for classifying practice. They are not a taxonomy to learn.

Related

• Interleaving Table — retrieval methods split by knowledge type; this page supplies the type variable
• Spaced Interleaved Retrieval — the retrieval system that takes the type variable
• Interleaving for Complex Problem Solving — the declarative-bottleneck diagnosis applied: familiar drills, collapse in context
• Knowledge Mastery From Recognition to Usable Knowledge — grades the declarative side
• Rapid Skill Acquisition — theory-to-practice pacing: working understanding, then the attempt
• Kolbs Experiential Cycle — the try–reflect–refine loop: what happened, how it felt and why, what rule that suggests, what changes next time
• Global Workspace and J-space — why proceduralized skill resists verbal report: it left the workspace

Open questions

• How should informed-strategy instruction that does teach the when and why be treated, given this vault’s subset stance?

Sources

• Anderson, J. R. (1982/1983). Acquisition of cognitive skill / The Architecture of Cognition. Declarative versus procedural stores; compilation can lose verbal access.
• Ryle, G. (1949). The Concept of Mind. Knowing-that and knowing-how.
• Paris, S. G., Lipson, M. Y., & Wixson, K. K. (1983). Becoming a strategic reader. Contemporary Educational Psychology. Declarative (what), procedural (how), conditional (when/why).
• Paris, S. G., & Jacobs, J. E. (1984). The benefits of informed instruction for children’s reading awareness and comprehension skills. Child Development. Strategy instruction that treats the when/why as teachable — the bound on this page’s subset stance.
• Shea, J. B., & Morgan, R. L. (1979). Contextual interference effects on the acquisition, retention, and transfer of a motor skill. Journal of Experimental Psychology: Human Learning and Memory. Varied practice grows discrimination.
• Taylor, K., & Rohrer, D. (2010). The effects of interleaved practice. Applied Cognitive Psychology.
• Rohrer, D., Dedrick, R. F., & Stershic, S. (2015). Interleaved practice improves mathematics learning. Journal of Educational Psychology. Familiar blocked drills, collapse on mixed transfer.
• Driskell, J. E., Copper, C., & Moran, A. (1994). Does mental practice enhance performance? Journal of Applied Psychology. Mental practice can move procedure a little.