Towards an Authentically Assessed Science Curriculum

Abstract

The intentions of the science curriculum are very often constrained by the forms of student learning that are required by, or are currently available within, the system of education. Furthermore, little attention is given to developing new approaches to assessment that would encourage these good intentions. In this chapter, we argue that achieving this broadening of the intentions of science education will require a diversity of assessment techniques and that only a profile of each student’s achievement will capture the range of intended learnings. We explore a variety of assessment modes that match some of these new aspects of science learning and that also provide students with both formative information and a more comprehensive and authentic summative profile of their performances. Our discussion is illustrated with research-based examples of assessment practice in relation to three aspects of science education that are increasingly referred to in curriculum statements as desirable human dimensions of science: context-based science education, decision-making processes and socioscientific issues and integrated science education. We conclude with some notes on what these broader kinds of assessment mean for teachers and the support they would need to include them in their day-to-day practices in the science classrooms if, and when, the mainstream of science teaching and learning takes these curricular intentions seriously.

Appendices

Appendix 1: Extended Response Task for Context-Based Assessment

(Source: Fensham, 2011, personal communication, adapted from an Extended Response Task used in Queensland schools)

Vehicular Motion

Introduction

Fundamental to the performance of any motor vehicle is how well it grips the road. Tyre and brake performance, friction and road surface conditions all have a part to play in determining how well a vehicle performs. In this extended response task, you are required to investigate these and other aspects relating to the performance and safety of modern motor vehicles. By the end of this task, you should have a good understanding of how tyre skid marks left at a motor vehicle accident scene can help determine who is at fault in an accident.

Part A: Knowledge and Conceptual Understanding

Task 1a. Explanation of Concepts Associated with Vehicular Motion

Investigate and provide written explanation of the concepts and processes listed below. Your explanation should include a scientific description of the concepts and an example of how they relate to vehicular motion.

Acceleration	Equations of motion	Reaction time
Coefficient of sliding friction	Newton’s First Law	Reaction distance
Friction force	Newton’s Second Law	Braking distance
Tyre tread	Newton’s Third Law	Vehicle stopping distance

Task 1b. Scenario

A driver undergoing safety training brings a vehicle initially travelling at a constant velocity to rest over 55.2 m. The driver’s reaction time is 1.2 s and the coefficient of sliding friction is 0.7. Tyre marks are left on the road. Calculate (a) the vehicle’s initial speed, (b) the vehicle’s reaction time, (c) the vehicle’s braking distance and (d) the length of tyre skid marks. (Show all working.)

Task 2. Explanation of Concepts Associated with Vehicular Motion

Reflecting upon your understanding of the concepts associated with vehicular motion, formulate a list of factors that would affect the braking performance of a modern motor vehicle. For each factor in your list, justify how it relates to the braking performance of the vehicle (250 words maximum).

Task 3. Scenario

As a leading traffic engineer, you are commissioned to write an article titled Factors Affecting Motor Vehicle Braking Performance in Wet Weather on Concrete Pavements for a leading scientific publication. Use the information you have gathered during the research task above to write the article. The article must be between 600 and 700 words in length, contain tables and/or graphs and be referenced as for your school’s standard reference policy.

Part B: Investigative Processes

Task 4a. Analysis of Secondary Data

Refer to the experimental data in the table below for skid mark length and initial speed at various coefficients of friction. Use Microsoft Excel or your Casio Class pad calculator to graph the initial speed versus skid mark length at each of the coefficients of friction.

Qualitatively describe the relationship between initial speed and skid mark length. Is a linear relationship a good approximation? What effect does the coefficient of friction have? Justify all conclusions.

Length of skid mark and initial speed data for various coefficients of friction

μ = 0.4		μ = 0.6		μ = 0.8
Length of skid mark (s) in m	Initial speed (u) in m/s	Length of skid mark (s) in m	Initial speed (u) in m/s	Length of skid mark (s) in m	Initial speed (u) in m/s
3.0	4.8	3.0	5.9	3.0	6.9
7.0	7.4	7.0	9.1	7.0	10.5
10.0	8.9	10.0	10.8	10.0	12.5
20.0	12.5	20.0	15.2	20.0	17.7
30.0	15.0	30.0	18.9	30.0	21.6
40.0	17.9	40.0	21.6	40.0	25.1
50.0	19.8	50.0	24.2	50.0	28.1

Task 4b. Analysis of Secondary Data

Investigate the theoretical relationship between the initial speed of a vehicle which slides to a halt and the length of its skid marks. Show how this relationship is derived.

Reflect upon the answer that you provide in Task 4a. Does the theoretical relationship agree with your conclusion?

Task 4c. Formulation of a Justifiable Question

Using your research, formulate a hypothesis that could be used as a basis for an investigation into the relationship between initial speed of a vehicle and length of skid marks.

Part C: Evaluating and Concluding

Task 5. Exploration of a Scenario

Introduction

An important aspect of automobile accident reconstruction is the analysis of tyre track skid marks.

The length of skid marks, along with data on a car’s tyres and the road surface, allows an accident reconstruction engineer to make a good estimate of a car’s speed just before the driver hits the brakes.

This information can assist in determining who is at fault in an accident.

The Scenario

You are a senior traffic incident investigation officer with the Queensland Police Force and have been called to the scene of a serious accident.

The incident involves a motorcycle and a car at the intersection of Charles and Camilla Streets.

Although the two vehicles narrowly avoided colliding, the sole passenger riding in the car was unrestrained and was flung from the front passenger seat into the dashboard, sustaining injuries and was rushed to hospital. The motorcycle rider and the driver of the car were uninjured.

Witness statements were recorded by uniformed police immediately after the incident.

From these statements the following is clear:

• 1. The motorcycle was heading south along Charles St and went through the set of traffic lights just as they were turning amber.

• 2. The car was heading east along Camilla St.

• 3. Both vehicles screeched to a halt and narrowly avoided colliding.

You have also received a call from a senior emergency doctor at the hospital. She is concerned as the female passenger has sustained internal injuries.

In order to have a better understanding of the stresses imposed on her internal organs during the collision with the dashboard, the doctor needs to know the relative speed with which the female passenger hit the dashboard.

Task 5a. Exploration of a Scenario

Calculate the relative speed with which the female passenger hit the dashboard (assume that the distance from the front seat to the dashboard is 1,500 mm). The diagram provided below may assist you in answering this question (show all your working). Assume that the coefficient of sliding friction for the car is 0.92 and for the motorcycle is 0.85.

Diagram of collision as witnessed by a ground-based observer

Task5b. Exploration of a Scenario

In a report of no more than 300 words, state whether you believe charges need to be laid on either driver. Justify your conclusion with scientific reasoning (you will need to refer to the diagram of the incident scene shown below).

Appendix 2: Reflective Judgement Interview Standard Probe Questions

(Source: Zeidler et al. 2009, p. 97)

Probe question	Purpose
1. What do you think about these statements?	To allow participants to share an initial reaction to the problem presented. Most state which point of view is closer to their own
Note: If no particular point of view is endorsed, ask 1a) Could you ever say which was the better position? How? Why not?
How would you go about making a decision about this issue? Will you ever know for sure which is the better position? How? Why not?
2. How did you come to hold this point of view?	To find out how the respondent arrived at the point of view and whether and how it has evolved from other positions on the issue
3. On what do you base that point of view?	To find out about the basis of the respondent’s point of view, such as personal evaluation of the data, consistency with the expert’s point of view or a specific experience. This provides information about the respondent’s concept of justification
4. Can you ever know for sure that your position on this issue is correct? How or why not?	To find out about assumptions concerning the certainty of the knowledge (e.g. whether issues like this can be known absolutely and what the respondent would do in order to increase the certainty, or why that would not be possible)
5. When two people differ about matters such as this, is it the case that one opinion is right and one is wrong?	Assesses the adequacy of alternative interpretations: to see if dichotomous either/or view of the issue (characteristic of the early stages) is held; to allow the participant to give criteria by which she/he evaluates the adequacy of arguments (information that helps differentiate high- from middle-level stage responses)
If yes, what do you mean by ‘right’? If no, can you say that one opinion is in some way better than the other? What do you mean by ‘better’?
6. How is it possible that people have such different points of view about this subject?	To elicit comments about the respondent’s understanding of differences in perspectives and opinions (what they are based on and why there is such diversity of opinion about the issue)
7. How is it possible that experts in the field disagree about this subject?	To elicit the respondent’s understanding of how she/he uses the point of view of an expert or authority in making decisions about controversial issues (such as whether experts’ views are weighted more heavily than others’ views, and why or why not)

Appendix 3: Sample NOS Assessment Question

(Source: Allchin 2011, p. 520)

Revised Mammogram Recommendations, November, 2009

A female acquaintance of yours is just turning 40. Concerned about the possibility of breast cancer, she had planned to get a mammogram in the next few months, despite her fears about excessive radiation. She has heard that a major national task force now advises waiting until 50 yet finds reassurance in Women’s Health Magazine about still following the old guidelines.

You both knew another woman who was diagnosed unexpectedly with breast cancer at age 43 and died last year. Your acquaintance is unsure how to interpret the apparently conflicting information and asks your help. What analysis of this reported change in scientific consensus would you provide to inform her decision?

Resource documents: (web addresses provided for each document)

• Women’s Health magazine article (Feb. 6, 2010)

• New York Times article (Nov. 17, 2009)

• US Preventive Services Task Force report, recommendation & supporting statement (Nov. 2009).

• Editorial published in Annals of International Medicine (Feb.15, 2009)

• Editorial published in Annals of International Medicine (Feb.15, 2010)

This question links to nine of the ten Dimensions of Reliability in Science in Allchin’s (2011, p. 525) scoring rubric.

Appendix 4: Star Diagrams of Dimensions of Assessment

Fig. 5.1

Six dimensions of assessment for reasoning about socioscientific issues (After Simonneaux 2010)

Fig. 5.2

Star diagram assessing performance on six dimensions of assessment for reasoning about socioscientific issues