AS 91521 Annotated exemplars

This annotated exemplar is intended for teacher use only. Annotated exemplars are extracts of student evidence, with commentary, that explain key parts of a standard. These help teachers make assessment judgements at the grade boundaries.

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TKI Physics assessment resources (external link)

For Excellence, the student needs to carry out a comprehensive practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves a discussion which addresses issues critical to the practical investigation, such as:

• the other variables that could have changed and significantly affected the results and how they could have changed the results
• limitations to the theory’s applicability
• unexpected outcomes, how they were caused and the effect they had on the validity of the conclusion.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

This student has provided a discussion on the applicability of the theory of simple harmonic motion to a child bouncing in a baby bouncer (1).

This student has provided a discussion on unexpected outcomes, how they were caused and the effect they could have on the validity of the conclusion (2).

For a more secure Excellence, this student could clearly discuss how other variable(s) were controlled, such as external forces or spring constant, and how they could have changed and significantly affected the results.

For Merit, the student needs to carry out an in-depth practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves:

• describing the control of other variable(s) that could significantly affect the results
• using techniques to improve the accuracy of measurements
• determining uncertainties in one of the variables expressed in the graphical analysis
• graphical analysis which expresses the uncertainty in the relationship consistent with the uncertainty in the data
• providing a conclusion that makes a quantitative comparison between the physics theory and the relationship/quantity obtained from the experimental data which includes consideration of uncertainties.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

The student has described the control of a variable that could significantly affect the results, i.e. the starting point of the bounce (1), used techniques to improve the accuracy of measurements, i.e. repeating measurements (2), and determined uncertainties in one of the variables expressed in the graphical analysis, i.e. the mass and the time period (3).

This student has also carried out a graphical analysis which expresses the uncertainty in the relationship consistently with the uncertainty in the data, i.e. using error bars and an error line (4), and provided a conclusion that makes a quantitative comparison between the physics theory and the gradient obtained from the experimental data, which includes the consideration of uncertainties (5).

To reach Excellence, this student could discuss limitations to the applicability of the theory of simple harmonic motion to the child bouncing in a baby bouncer. For example, the student could explain why the baby’s movement sideways would limit the comparison of its movement to that of simple harmonic motion.

For Merit, the student needs to needs to carry out an in-depth practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves:

• describing the control of other variable(s) that could significantly affect the results
• using techniques to improve the accuracy of measurements
• determining uncertainties in one of the variables expressed in the graphical analysis
• graphical analysis which expresses the uncertainty in the relationship consistent with the uncertainty in the data
• providing a conclusion that makes a quantitative comparison between the physics theory and the relationship/quantity obtained from the experimental data which includes consideration of uncertainties.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

This student has used techniques to improve the accuracy of measurements, i.e.  repeating and multiple measurements (1), and determined the uncertainty in the variables expressed in the graphical analysis, i.e. the mass and the time period (2).

This student has also used graphical analysis which expresses the uncertainty in the relationship consistent with the uncertainty in the data, i.e. drawing a line of best fit, error bars and an error line (3), and attempted to provide a conclusion that makes a quantitative comparison between the physics theory and the quantity obtained from the experimental data, i.e. the gradient (4).

For a more secure Merit, this student could describe, in more detail, the control of other variable(s) that could significantly affect results, such as the spring constant or the distance the spring is pulled.

For Achieved, the student needs to needs to carry out a practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves:

• collecting data relevant to the aim
• determining uncertainties in the raw data
• using graphical analysis, including a consideration of uncertainties, from which the equation of the relationship/ value of the physics quantity can be determined
• providing a conclusion that states the equation of the relationship/value of the physics quantity as determined from the graph, and includes a comparison with the physics theory.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

This student has collected data which is relevant to the aim (1), determined the uncertainty in the raw data, i.e. for the mass and the time (2), and used graphical analysis, including a consideration of uncertainties, i.e. plotted both error bars and an error line (3). 

This student has also provided a conclusion that states equation for the relationship (4), and attempts to compare the physics theory with the value of a physics quantity, i.e. ‘k’, the spring constant, as determined from the graph (5).

To reach Merit, this student could provide a conclusion that makes a quantitative comparison between the physics theory and the relationship obtained from the data which includes consideration of uncertainties.

For Achieved, the student needs to needs to carry out a practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves:

• collecting data relevant to the aim
• determining uncertainties in the raw data
• using graphical analysis, including a consideration of uncertainties, from which the equation of the relationship/ value of the physics quantity can be determined
• providing a conclusion that states the equation of the relationship/ value of the physics quantity as determined from the graph and includes a comparison with the physics theory.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

This student has collected data which is relevant to the aim (1), determined the uncertainty in the raw data, i.e. the mass (2), and started to use graphical analysis to determine the equation for relationship (3).

This student has also provided a conclusion that attempts to include a comparison between the physics theory and the equation of the relationship as determined from the graph (4).

For a more secure Achieved, this student could improve the testing of the physics theory by:

• determining accurately the uncertainty in time measurements, for example by dividing the time range by 2, or
• describing in more detail how the graph was analysed, in order to determine the gradient from which the equation of the relationship was determined.

For Achieved, the student needs to needs to carry out a practical investigation to test a physics theory relating two variables in a non-linear relationship.

This involves:

• collecting data relevant to the aim
• determining uncertainties in the raw data
• using graphical analysis, including a consideration of uncertainties, from which the equation of the relationship/ value of the physics quantity can be determined
• providing a conclusion that states the equation of the relationship/ value of the physics quantity as determined from the graph and includes a comparison with the physics theory.

This student is testing the theory of simple harmonic motion as it applies to a child bouncing in a baby bouncer.

This student has collected data which is relevant to the aim (1), determined appropriate uncertainties in the raw data, i.e. drawn the error bars for the mass on the graph (2), and stated the equation for the relationship (3).

To reach Achieved, this student could provide a conclusion that includes a comparison between the physics theory and the equation of the relationship/value of the physics quantity, as determined from the graph.