science

Tacit assumption

Tacit assumption is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Tacit assumption rather than just read about it. In short: A tacit assumption or implicit assumption is an assumption that underlies a logical argument, course of action, decision, or judgment that is not explicitly voiced nor necessarily understood by the decision maker or judge. These assumptions may be made based on personal life experiences, and are not consciously apparent in the decision making environment.

Key takeaways

Tacit assumption belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tacit assumption to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tacit assumption from memory before moving on to harder problems.

Reference excerpt

A tacit assumption or implicit assumption is an assumption that underlies a logical argument, course of action, decision, or judgment that is not explicitly voiced nor necessarily understood by the decision maker or judge. These assumptions may be made based on personal life experiences, and are not consciously apparent in the decision making environment. These assumptions can be the source of apparent paradoxes, misunderstandings and resistance to change in human organizational behavior. Tacit assumptions in science often include the elegance of natural laws, and the applicability of mathematics.

Worked examples

Example 1 — a first encounter with Tacit assumption

Start with the simplest possible case. Write down what Tacit assumption claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Tacit assumption before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Tacit assumption ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Tacit assumption

In research: Tacit assumption appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Tacit assumption in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Tacit assumption is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ignorance, Logic, Logic stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Tacit assumption outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Tacit assumption in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tacit assumption means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Tacit assumption out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tacit assumption in simple terms?

Why does Tacit assumption matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Tacit assumption?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Tacit assumption.