Scientific Method – Quick Theory

The Scientific Method is a logical, step-wise process used to investigate phenomena, acquire new knowledge or correct existing knowledge. It starts with observation of a natural event, followed by formulation of a question and a hypothesis (a testable, falsifiable explanation). The hypothesis is then tested through controlled experiments or further observations. Data collected are analysed statistically to decide whether the hypothesis is supported or rejected. Finally, results are communicated (peer-reviewed journals, conferences) so others can replicate and validate the work. Reproducibility and objectivity are its pillars; personal bias is minimised by standardised protocols and blinding.

Although the classic sequence is Observation → Question → Hypothesis → Experiment → Data → Conclusion → Communication, real science is iterative. Unexpected results can send the investigator back to re-frame the hypothesis or design a new experiment. Variables are of three types: independent (manipulated), dependent (measured) and controlled (kept constant). A controlled experiment changes only one independent variable at a time while keeping all others constant. Theories are hypotheses that have survived extensive testing and explain wide ranges of phenomena (e.g., germ theory of disease). Laws describe what happens under certain conditions, whereas theories explain why it happens.

Practice MCQs

1. The first step of the scientific method is
   A. Hypothesis
   B. Experiment
   C. Observation
   D. Conclusion

2. A testable explanation to a question is called
   A. Theory
   B. Law
   C. Hypothesis
   D. Result

3. Which variable is deliberately changed by the experimenter?
   A. Controlled
   B. Dependent
   C. Independent
   D. Constant

4. In a controlled experiment, all variables should be kept constant except the
   A. Dependent variable
   B. Independent variable
   C. Control group
   D. Hypothesis

5. The group that does NOT receive the experimental treatment is the
   A. Test group
   B. Control group
   C. Variable group
   D. Trial group

6. A hypothesis that has been repeatedly tested and supported becomes a
   A. Guess
   B. Law
   C. Theory
   D. Model

7. Which statement best describes a scientific theory?
   A. An educated guess
   B. A proven fact
   C. A well-supported explanation of some aspect of nature
   D. A single experiment result

8. The step after experimenting is
   A. Observation
   B. Data analysis
   C. Hypothesis
   D. Question

9. Reproducibility of results by other scientists ensures
   A. Bias
   B. Objectivity
   C. Subjectivity
   D. Profit

10. A scientific law
    A. Explains why something happens
    B. Describes what happens under certain conditions
    C. Cannot be expressed mathematically
    D. Is less certain than a hypothesis

11. Peer review is done primarily to
    A. Increase journal sales
    B. Get government funding
    C. Validate and improve scientific work
    D. Promote the author

12. Which is NOT a characteristic of a good hypothesis?
    A. Testable
    B. Falsifiable
    C. Vague
    D. Based on prior knowledge

13. An experiment shows that plants grow faster with music. This is an example of
    A. A law
    B. An observation
    C. A conclusion
    D. A hypothesis under test

14. The dependent variable in “effect of fertiliser on plant height” is
    A. Type of fertiliser
    B. Plant height
    C. Sunlight hours
    D. Soil type

15. Double-blind trials are used to eliminate
    A. Independent variable
    B. Experimental bias
    C. Control group
    D. Replication

16. A scientist repeats an experiment 10 times to
    A. Waste time
    B. Increase reliability
    C. Change the hypothesis
    D. Decrease accuracy

17. Which sequence is correct?
    A. Hypothesis → Observation → Experiment
    B. Observation → Hypothesis → Experiment
    C. Experiment → Conclusion → Observation
    D. Conclusion → Experiment → Hypothesis

18. If data do not support the hypothesis, the scientist should
    A. Hide the data
    B. Change the data
    C. Reject or modify the hypothesis
    D. Stop researching

19. A graph of continuous data is best shown with
    A. Bar graph
    B. Pie chart
    C. Line graph
    D. Flow chart

20. The statement “All organisms are made of cells” is a
    A. Hypothesis
    B. Theory
    C. Law
    D. Guess

21. Which error type can be reduced by increasing sample size?
    A. Systematic error
    B. Random error
    C. Calibration error
    D. Zero error

22. A hypothesis must be falsifiable means
    A. It can be proven true
    B. It can be proven false
    C. It is always true
    D. It is a law

23. The control in a drug trial is usually given
    A. Double dose
    B. Placebo
    C. Nothing
    D. Another drug

24. A scientific model
    A. Is always physical
    B. Never changes
    C. Simplifies reality to explain phenomena
    D. Is less accurate than a hypothesis

25. Which action violates scientific ethics?
    A. Recording all data
    B. Repeating experiments
    C. Fabricating results
    D. Sharing raw data with peers

Answers

1. Answer

   Correct: C. Observation is the initial recognition of an event or pattern.
2. Answer

   Correct: C. Hypothesis is a tentative, testable explanation.
3. Answer

   Correct: C. Independent variable is manipulated to see its effect.
4. Answer

   Correct: B. Only the independent variable is changed; others are controlled.
5. Answer

   Correct: B. Control group serves as baseline for comparison.
6. Answer

   Correct: C. Extensive support elevates a hypothesis to a theory.
7. Answer

   Correct: C. Theories integrate many tested hypotheses.
8. Answer

   Correct: B. After collecting data, we analyse them to draw conclusions.
9. Answer

   Correct: B. Reproducibility minimises subjective error and confirms validity.
10. Answer

    Correct: B. Laws summarise observable relationships (e.g., Boyle’s law).
11. Answer

    Correct: C. Peer review checks flaws, ensures quality and validity.
12. Answer

    Correct: C. Vague statements cannot be tested or falsified.
13. Answer

    Correct: D. The music effect is a hypothesis being tested, not yet a law.
14. Answer

    Correct: B. Height depends on fertiliser, hence dependent variable.
15. Answer

    Correct: B. Neither investigator nor participant knows who gets treatment, reducing bias.
16. Answer

    Correct: B. Replication improves reliability and statistical power.
17. Answer

    Correct: B. Observation triggers question, then hypothesis, then test.
18. Answer

    Correct: C. Integrity demands revising or rejecting unsupported hypotheses.
19. Answer

    Correct: C. Line graphs show trends in continuous data.
20. Answer

    Correct: B. Cell theory is a well-substantiated explanation.
21. Answer

    Correct: B. Random errors average out with larger samples.
22. Answer

    Correct: B. Falsifiability means conceivable observation could show it wrong (Popper).
23. Answer

    Correct: B. Placebo controls for psychological effects.
24. Answer

    Correct: C. Models are simplifications aiding understanding and prediction.
25. Answer

    Correct: C. Fabrication is scientific misconduct.

Railway-Exam Shortcuts & Tips

1. Memory chain: “Oh Hello Everyone, Data Comes Too” → Observation, Hypothesis, Experiment, Data, Conclusion, Theory.
2. Variables trick: Independent = I change; Dependent = Data measured; Controlled = Constant.
3. Theory vs Law: Theory explains ‘why’ (T-E-X-P-L-A-I-N), Law states ‘what’ (L-A-W = short, descriptive).
4. Elimination rule: Options with “always”, “never”, “only” are usually wrong in science-method questions.
5. Peer review & ethics appear every year—remember: transparency, replication, falsifiability are golden keywords.