Notes on Genres - Theoretical Explanation

Function

To explain why the phenomenon happens relating to physics theories, principles or laws. It puts special emphasis on the relationship between the observations and physics theories/principles/laws.

Schematic Structure

Statement of Theory ^ Explanation Sequence [1-n] ^ Conclusion

Examples

2012 DSE 1B Q2b, 2013 1B Q1c, 2013 DSE 1B Q4b, 2013 1B Q6b, 2013 DSE 1B Q6c, 2013 DSE 1B Q7b(i), 2013 DSE 1B Q7c

Common vocabulary and sentence patterns used in setting questions

Use ...... theory to explain ......
In terms of ......, explain why......
Explain

Genre Structure and language features

Schematic Structure	Contents and Functions	Language features
Statement of Theory	State clearly the theory, law, or principle relating to the event or phenomenon	Quoting the direction as the aim of the procedure According to...
Explanation Sequence	Relate the concepts to the events or phenomena. In addition, explanation of the various characteristics with causal relation may be used.	Relate the phenomena with "when", "because", "since" to the theory Causal conjunctions, "hence", "thus", "and", "lead to" for the causal relations
Conclusion (optional)	Summarize the explanation	Conjunctions "Therefore", "Hence" and "Thus" always bring out the conclusion

Schematic Structure

Contents and Functions

Language features

Statement of Theory

State clearly the theory, law, or principle relating to the event or phenomenon

Quoting the direction as the aim of the procedure

According to...

Explanation Sequence

Relate the concepts to the events or phenomena.

In addition, explanation of the various characteristics with causal relation may be used.

Relate the phenomena with "when", "because", "since" to the theory

Causal conjunctions, "hence", "thus", "and", "lead to" for the causal relations

Conclusion (optional)

Summarize the explanation

Conjunctions "Therefore", "Hence" and "Thus" always bring out the conclusion

Example of Theoretical Explanation writing

Use kinetic theory to explain the change in gas pressure in the bubble as its volume increases. (Source: HKEAA 2012 DSE 1B Q2b)

According to the kinetic theory, gas pressure is due to the collision of gas molecules on the inner wall of the bubble. Because the gas temperature remains unchanged, the average speed of gas molecules remains unchanged. When a gas bubbles rises up, its volume increases. Therefore, the frequency of collision of the gas molecules on the inner surface of the bubble decreases, which results in the decrease of gas pressure.

Analysis of Theoretical Explanation writing

Schematic Structure	Text	Linguistic Features
Statement of Theory	According to the kinetic theory, gas pressure is due to the collision of gas molecules on the inner wall of the bubble.	Circumstance, "According to the kinetic theory" states a related theory.
Explanation Sequence 1	Because the gas temperature remains unchanged, the average speed of gas molecules remains unchanged.	Causal "Because" links the macro-world to micro-world.
Explanation Sequence 2	When a gas bubbles rises up, its volume increases. Therefore, the frequency of collision of the gas molecules on the inner surface of the bubble decreases, which results in the decrease of gas pressure.	Adversative conjunction, "When" turns to a situation. Causal conjunction "Therefore" brings out the conclusion. Causal conjunction "results in" for further elaboration

Schematic Structure

Text

Linguistic Features

Statement of Theory

According to the kinetic theory, gas pressure is due to the collision of gas molecules on the inner wall of the bubble.

Circumstance, "According to the kinetic theory" states a related theory.

Explanation Sequence 1

Because the gas temperature remains unchanged, the average speed of gas molecules remains unchanged.

Causal "Because" links the macro-world to micro-world.

Explanation Sequence 2

When a gas bubbles rises up, its volume increases. Therefore, the frequency of collision of the gas molecules on the inner surface of the bubble decreases, which results in the decrease of gas pressure.

Adversative conjunction, "When" turns to a situation.

Causal conjunction "Therefore" brings out the conclusion.

Causal conjunction "results in" for further elaboration