Nature of Science
This page covers the Nature of Science — the scientific method, science process skills, and the key measurement scales used in science — for REET. REET has tested general science awareness from this topic, such as the scale used to measure earthquakes and major natural disasters.
- 2 questions in REET 2024
- Class 6-8 level content
- 9 min read
How REET actually asks this topic
REET 2024 carried two questions from this topic, and both were general-science-awareness type. The first asked which scale measures the magnitude of an earthquake (answer: the Richter scale), and the second asked you to identify the natural disaster that struck Bhuj in Gujarat on 26 January 2001 (answer: an earthquake). This makes it clear that under the heading 'Nature of Science', REET also tests general awareness of measurement scales used in science and major science-related events — not just definitions of the scientific method. So prepare both the core understanding of the scientific method and process skills, and general science awareness (measurement scales, well-known natural events) for this topic.
The nature of science and the scientific method
Science is a systematic, factual, and verifiable body of knowledge, built on observation and experiment. Its key features are: it is objective — based on evidence rather than personal opinion; it is universal — the same conditions produce the same results anywhere; and it is tentative (self-correcting) — existing theories can be revised or replaced when new evidence comes to light.
Any scientific investigation generally follows this sequence: observation (carefully noticing a phenomenon), identifying the problem, forming a hypothesis (an initial, testable guess at the answer), testing the hypothesis through experiment, and finally drawing a conclusion. This step-by-step process is called the scientific method, and teaching students to think in this same sequence is what's meant by developing 'scientific temper'.
Understanding the difference between observation and inference is also an important part of the nature of science. An observation is something directly seen, heard, or measured by the senses — for instance, 'the plant's leaves have turned yellow'. An inference, on the other hand, is an interpretation of that observation, drawing on prior knowledge — for instance, 'the leaves have probably turned yellow from lack of water'. In science, it's important to remember that an inference is always a possibility that goes beyond the observation, not a certain truth — which is why it needs to be tested further through experiment.
Scientific temper and the Constitution
- Article 51A(h)
- Among the Fundamental Duties in the Indian Constitution, Article 51A, clause (h), places a duty on every citizen to develop a scientific temper, humanism, and the spirit of inquiry and reform.
- Importance in education
- This is exactly why school science teaching is considered to be about more than memorising facts — it is also meant to develop reasoning grounded in evidence, i.e., scientific temper, in students.
Science process skills
- Basic skills
- Observation, classification, measurement, communication — these are the foundational skills with which science teaching begins, and they should be practised from the earliest classes onward.
- Higher-order skills
- Inference/prediction, forming a hypothesis, controlling variables, planning and carrying out experiments, and analysing the data collected to draw conclusions.
- Importance in teaching
- The goal of science teaching is not just to have students memorise facts, but to build — through these skills — the capacity to think independently, ask questions, and verify claims using evidence, a capacity that remains useful throughout life and helps in everyday decision-making.
Key measurement scales used in science
| Quantity | Scale / unit used to measure it |
|---|---|
| Magnitude of an earthquake | Richter scale |
| Loudness of sound | Decibel scale (dB) |
| Temperature | Kelvin scale (SI unit); Celsius is also common in everyday use |
| Pressure | Pascal (SI unit) |
A key example of a natural disaster: the Bhuj earthquake
- Date and location
- 26 January 2001, Bhuj (Kutch district), Gujarat[Source 2]
- Type and cause
- A devastating earthquake caused by tectonic movement in the Earth's crust, whose magnitude was measured on the Richter/moment-magnitude scale.[Source 2]
- Significance
- One of India's most devastating earthquakes, which caused massive loss of life and property, and prompted a rethink of the country's disaster-management policies and building-construction standards (earthquake-resistant construction) — it's a historical example frequently asked about in the general-science-awareness context in REET and other exams.
How to teach this to children
Classroom activity
Have students measure and record the height of a potted plant every day in class, and after a few days ask them what hypothesis they can form from that data — a simple, low-cost activity that teaches several process skills at once: observation, measurement, communication and inference.
Teaching aids
Put up a simple flowchart of the steps in the scientific method (observation → hypothesis → experiment → conclusion) in the classroom, and build the habit of investigating every science lesson in this same order, so it becomes a lasting way of thinking rather than just an exam answer.
Common misconception
Many students — and sometimes teachers too — assume science is just a collection of memorised facts and formulas, or that scientific theories are always final and unchangeable truths. Make it clear that science is really a process of inquiry, where asking questions and seeking evidence-based answers is central, and that theories can change when new evidence emerges.
Assessment idea
Give students a familiar everyday phenomenon (such as 'ice floats on water') and ask them to write one observation, one hypothesis, and one possible experiment about it — and check whether they are correctly distinguishing observation from inference.
Memory trick / exam tip
Pair up the measurement scales to remember them — earthquake–Richter, sound–decibel, temperature–Kelvin, pressure–Pascal. REET often swaps these scales around to create tricky distractors (like offering decibel or Pascal as an option for earthquakes), so keep the correct scale for each quantity clear in your mind and don't rush your choice. It also helps to note down the date and location of major natural disasters (like the Bhuj earthquake) separately, the way you would for general knowledge.
REET 2024 questions (with solutions)
Question 132
Which of the following scale is used for the measurement of magnitude of the power of an earthquake ?
- Aकेल्विन पैमाना
- Bडेसीबल पैमाना
- Cपास्कल पैमाना
- Dरिक्टर पैमाना
Explanation
भूकम्प की शक्ति का परिमाण (magnitude) रिक्टर पैमाने (Richter scale) पर व्यक्त किया जाता है, जो सीस्मोग्राफ के आँकड़ों पर आधारित लघुगणकीय पैमाना है। केल्विन ताप का, डेसीबल ध्वनि की प्रबलता का और पास्कल दाब का मात्रक/पैमाना है।
Question 148
Natural disaster by which many people are affected on 26 January 2001 in Bhuj city of Gujarat is
- Aज्वालामुखी
- Bभूकम्प
- Cबाढ़
- Dतड़ित
Explanation
26 जनवरी 2001 को गुजरात के भुज (कच्छ) क्षेत्र में विनाशकारी भूकम्प आया था, जिससे बड़ी संख्या में लोगों की मृत्यु हुई और भारी क्षति हुई। अतः सही उत्तर भूकम्प है।
Practice questions
Question 1
The correct sequence of the scientific method is:
- Aपरिकल्पना → प्रेक्षण → प्रयोग → निष्कर्ष
- Bप्रेक्षण → परिकल्पना → प्रयोग → निष्कर्ष
- Cप्रयोग → निष्कर्ष → प्रेक्षण → परिकल्पना
- Dनिष्कर्ष → प्रयोग → परिकल्पना → प्रेक्षण
Explanation
The scientific method starts with observing a phenomenon, then forms a hypothesis about its probable cause, then tests that hypothesis through experiment, and finally draws a conclusion.
Question 2
Which of the following is NOT a science process skill?
- Aप्रेक्षण
- Bवर्गीकरण
- Cरटना (बिना समझे याद करना)
- Dअनुमान लगाना
Explanation
Observation, classification and inference are all science process skills, grounded in understanding and investigation. Rote memorisation without understanding runs against the nature of science, which promotes evidence- and reasoning-based thinking.
Question 3
Which scale is used to measure the magnitude of an earthquake?
- Aडेसीबल पैमाना
- Bकेल्विन पैमाना
- Cरिक्टर पैमाना
- Dपास्कल पैमाना
Explanation
The magnitude of an earthquake is measured on the Richter scale, a logarithmic scale based on data from a seismograph.
Question 4
The loudness of sound is measured on which scale?
- Aडेसीबल
- Bरिक्टर
- Cपास्कल
- Dकेल्विन
Explanation
The loudness (intensity) of sound is measured on the decibel (dB) scale.
Question 5
What is the SI unit/scale for measuring temperature?
- Aपास्कल
- Bडेसीबल
- Cकेल्विन
- Dरिक्टर
Explanation
The international standard (SI) unit for measuring temperature is Kelvin (K), although the Celsius scale is also widely used in daily life.
Question 6
What is the SI unit for measuring pressure?
- Aन्यूटन
- Bवाट
- Cजूल
- Dपास्कल
Explanation
The SI unit for measuring pressure is the pascal (Pa), which represents the force acting per unit area.
Question 7
On which date did the devastating earthquake occur in the Bhuj (Kutch) region of Gujarat?
- A26 जनवरी 2001
- B15 अगस्त 2001
- C26 जनवरी 1999
- D2 अक्टूबर 2001
Explanation
A devastating earthquake struck the Bhuj (Kutch) region of Gujarat on 26 January 2001, caused by tectonic movement, and it caused massive loss of life and property.
Question 8
The characteristic of science according to which older theories can be revised when new evidence emerges is called:
- Aस्थायी प्रकृति
- Bपरिवर्तनशील/स्वतः-सुधारक प्रकृति
- Cव्यक्तिपरक प्रकृति
- Dअपरिवर्तनीय प्रकृति
Explanation
Science's tentative/self-correcting nature means scientific theories are not final truths — they can be revised or changed based on new evidence and experiments.
Question 9
The most suitable way for a teacher to develop science process skills in the classroom is:
- Aकेवल पाठ्यपुस्तक के तथ्य रटवाना
- Bविद्यार्थियों को स्वयं प्रेक्षण व सरल प्रयोग करने के अवसर देना
- Cकेवल परीक्षा की तैयारी कराना
- Dप्रश्नों के उत्तर सीधे बता देना
Explanation
Science process skills (observation, inference, experimentation, etc.) only develop when students get the chance to observe and experiment for themselves, not when they are simply handed facts or answers to memorise.
Question 10
What does 'hypothesis' mean in the scientific method?
- Aअंतिम व सिद्ध निष्कर्ष
- Bपाठ्यपुस्तक में दी गई परिभाषा
- Cप्रयोग के उपकरणों की सूची
- Dप्रेक्षण के आधार पर बनाया गया प्रारंभिक, जाँचने योग्य अनुमान
Explanation
A hypothesis is an initial, testable guess formed on the basis of observation, which is later proved right or wrong through experiment — it is not a final conclusion.
Frequently asked questions
What are the steps of the scientific method?+
The scientific method generally includes these steps: observation, identifying the problem, forming a hypothesis, testing it through experiment, and drawing a conclusion.
What are science process skills?+
Skills such as observation, classification, measurement, inference, forming a hypothesis, experimenting and drawing conclusions — skills that build the capacity to think and investigate scientifically — are called science process skills.
What does the Richter scale measure?+
The Richter scale is used to measure the magnitude of an earthquake — it's a scale based on data from a seismograph.
When did the Bhuj earthquake occur?+
A devastating earthquake struck the Bhuj (Kutch) region of Gujarat on 26 January 2001, and it is counted among India's most devastating earthquakes.
What are the key features of science, and what is the difference between observation and inference?+
Science is objective (evidence-based), universal, and tentative/self-correcting (it can be revised when new evidence appears). Tied to this is the difference between observation and inference — an observation is something directly seen or measured with the senses, while an inference is an interpretation of that observation, which needs to be tested further by experiment. Under Article 51A(h) of the Indian Constitution, developing scientific temper is also a Fundamental Duty of every citizen.
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Official Sources
Change Log
- 17 September 2026 — English page published — mirrors the fact-checked Hindi page, independently bilingual-accuracy checked