Science Extension 2021 HSC exam pack

Students should:

• read the question carefully to ensure that they understand the intent of the question and its requirements
• plan their response to assist in the logical sequencing of information
• use appropriate scientific language
• engage with any stimulus material provided and refer to it in their response
• show all working in calculations and include correct units
• review their response to ensure that it addresses the question requirements and contains no contradictions.

Question 1

In better responses, students were able to:

• critically evaluate the abstract to identify a variety of issues related to scientific research
• provide detailed explanations of issues that may lead to the rejection of an abstract
• demonstrate a good understanding of research methodologies.

Areas for students to improve include:

• detailing issues with the abstract rather than describing what the author should have done
• providing explanations of the issues rather than producing a list of concerns.

Question 2

In better responses, students were able to:

• differentiate between the meanings of inductive and deductive reasoning
• describe methods to test the proposal using inductive and deductive reasoning
• provide details on how data could be collected to test the proposal.

Areas for students to improve include:

• identifying which method (induction or deduction) is being used
• demonstrating an understanding of inductive and deductive testing, not just inductive and deductive reasoning
• demonstrating a clear understanding of the type of reasoning being described in a method.

Question 3

In better responses, students were able to:

• identify problems in the statistical techniques being applied and the data from both sources on which the hypothesis was based
• support their judgement with consistent reasons from an analysis of the data
• recognise the contemporary nature of the data and that the percentage change in the concentration of heavy metals may not be consistent over time.

Areas for students to improve include:

• critically analysing data to identify limitations in support for the hypothesis and affirmation of the hypothesis
• analysing the data in the sources to produce a judgement instead of a description of the data
• providing judgements using both sources.

Question 4

In better responses, students were able to:

• link experimental data and photographic techniques in the method to the type of data being collected and analysed
• apply appropriate statistical analysis and representation to both quantitative and qualitative experimental data
• apply the elements that make up an experimental design, including the need for techniques to confirm reliability.

Areas for students to improve include:

• distinguishing what constitutes quantitative and qualitative data in an experiment
• differentiating between descriptive data treatment and statistical analysis of data
• assigning appropriate representations to best display results of their quantitative and qualitative data
• ensuring the proposed hypothesis may be tested by the described experiment.

Question 5(a)

In better responses, students were able to:

• provide a detailed explanation of the political, economic and ethical factors that may influence the conduct of the experiment
• support the explanation with direct links to the map and video.

Areas for students to improve include:

• providing information from both the video and the map.

Question 5(b)

In better responses, students were able to:

• correctly interpret graphs and stimulus to provide a decision indicating whether scientists should continue with the experiment
• correctly interpret both p-values and the Pearson's correlation coefficient to the scenario
• demonstrate an understanding how data and statistics can be improved.

Areas for students to improve include:

• using all information provided in the stimulus to back up interpretations
• describing specific trends, patterns and statistics to support the decision to continue with the experiment
• providing a statement indicating how the data can be improved.

Question 5(c)

In better responses, students were able to:

• provide detailed explanations of more than one feature of using predictive data modelling
• link specific features of predictive data modelling to the study of the effect dingoes have on the diversity of species.

Areas for students to improve include:

• explaining how predictive data modelling can provide for the study of the effect dingoes have on the diversity of species, in terms of time, quantity of data and related variables
• providing details of the needs for predictive data models, not just data models.

Question 6

In better responses, students were able to:

• use relevant examples and clear links to their Scientific Research Project to explain ways in which science could maintain trust
• clearly link their examples to scientific processes with relevant scientific language
• use subheadings or effective paragraphs to demonstrate a connected, logical response.

Areas for students to improve include:

• explaining how trust in science can be built, rather than why science should be trusted.