GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 185
Assessment area
GCSE Additional Science: Investigation
Controlled Assessment
Mark
Awarded
Hypothesising &
planning / 12
Collecting, reviewing
& processing data / 12
Analysing & reviewing
procedure / 12
Analysing data &
concluding / 12
TOTAL / 48
Candidate Name ...............................................................................
Centre Name ......................................................................
Centre Number .. ...............
Declaration by candidate
I have read and understood the Notice to Candidates (GCSE and Principal Learning:
Controlled Assessments). I have produced the attached work without assistance other
than that which is acceptable under the scheme of assessment.
Candidate's name: ........................................................................................................
Candidate's signature: ...................................................
Date .................................
Declaration by teacher or lecturer
I confirm that:
1.
the candidate's work was conducted under the conditions laid out by the
specification;
2.
I have authenticated the candidate's work and am satisfied that, to the best of my
knowledge, the work produced is solely that of the candidate.
Teacher's name: ........................................................................................................
Teacher's signature: ...................................................
Year - SPECIMEN
Date .................................
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 186
Additional Science: Controlled Assessment
Investigating terminal velocity
When objects (including people) fall through the air, they accelerate until they reach a
maximum speed – known as the terminal velocity. For a human being falling without a
parachute this can be more than 100 m/s. On the other hand people claim that a mouse
dropped on to a flat surface will never reach a high enough speed for the impact to be
fatal.
There are all sorts of factors we can investigate, e.g.
y
y
y
How does the size of an object affect its terminal velocity?
How does the mass of an object affect its terminal velocity?
How far does an object fall before it reaches terminal velocity?
You'll be able to think of several more possibilities.
PART 1 – this part is not assessed
Before you do the assessed part of this controlled assessment you will consider the
third bullet point – how far does an object fall before it reaches terminal velocity. Rather
than drop a man or a mouse, you will use more easily replaced objects and ones which
are easier to handle, such as paper or aluminium cake cases. There are also fewer
ethical issues with this approach!
Your teacher will introduce the investigation and divide up the measurements among
different people.
When you have taken the measurements, you should produce a brief report containing:
y
y
your results and those of other people
an analysis of your results.
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 187
Investigating terminal velocity
PART 2 – this part is assessed
Now you are going to move on to investigate another question about terminal velocity. It
could be one of the first 2 bullet points in PART 1 or a different question.
You should
(a)
(b)
(c)
(d)
(e)
decide what question you are going to investigate – you can discuss this with other
people, including others taking the assessment,
research the topic, e.g. by looking for information on the internet,
produce a hypothesis and give some background information which supports it,
produce a plan for undertaking the investigation – you should use information from the
work in PART 1,
consider any risks associated with this investigation – you may use the Risk
Assessment sheet for this.
You will do parts (c), (d) and (e) under supervision and without discussing it with anyone
apart from your teacher.
You should now proceed to carry out the investigation and write it up. You will be able to cooperate with other people in obtaining data but the report must be your own work.
When carrying out your investigation, you should review your method and change it if
necessary in the light of experience.
Report
Your report should include:
y your hypothesis, plan and risk assessment
• a suitable presentation of all your results
y evaluations of the results and discussion of your findings
y conclusions and review of the hypothesis
y an evaluation of the investigation.
Risks
Ways of reducing risks
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Hazards
GCSE Additional Science – Risk Assessment
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 188
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 189
Teacher Guidance Notes
This controlled assessment task is in the context of sections 3 and 4 of the Physics 2
content, especially section 3(e). The task, including the preliminary work, is structured as
follows:
1.
Preliminary work. The candidates collectively investigate how far an object falls
before reaching terminal velocity. This is not assessed, but the experience of the
preliminary work and the results they obtain will be used to inform their planning for
the remaining part of the controlled assessment.
A possible approach to this preliminary work is to time light objects, e.g. cake cases,
as they fall from a series of different heights and to plot a graph of drop height
against time – the distance fallen before terminal velocity is reached can be read off
the graph.
height
The work can be split up, some groups of candidates investigating a different mass
of object, e.g. using, say, 3 nested cases. Candidates can be given the opportunity
to exchange results so that the repeatability and reproducibility of the measurements
can be investigated. During this preliminary part of the controlled assessment,
candidates may seek and be given detailed advice.
2.
Collection of secondary data. As part of the planning process, the candidates
need to collect secondary data. These data can be used by the candidates in two
ways: to inform themselves about the repeatability and reproducibility of the data
which could inform their decision about the number of repeats; to provide some
evidence which may be of use in their hypothesising. The secondary data may also
be useful in their analysis / evaluation. The results of other candidates in the
preliminary work could be used and supervisors could provide a data set for the
candidates to search. It is important that the candidates select appropriate data
for themselves. Centres having difficulty in obtaining appropriate data which may
be used should contact WJEC.
3.
Research. This stage of the controlled assessment is carried out under a limited
level of control. Candidates may carry out some work in conditions not under the
supervision of the teacher. The candidates should be given the opportunity to do
some research which can involve internet searches and text books into the factors
which affect the magnitude of the terminal velocity. They should be encouraged to
relate this to the work they have done on air resistance and weight and resultant
forces. Supervisors may prepare materials for candidates to use in this research
phase. Copies of these materials should be included with the candidates' work.
Entering the phrase terminal velocity into a search engine produces a plethora of
websites, several of which are very useful and at an accessible level.
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 190
4.
Planning an investigation. This stage of the controlled assessment is carried out
under a high level of control, i.e. the candidates work individually. The candidates
use the results of their research and their preliminary work to plan an investigation
into one of the factors which may affect the terminal velocity of a falling object. They
should
• Identify the variables which they intend to investigate
• Identify variables which need to be controlled
• Suggest a relationship between the dependent and independent variables
• Give reasons for suggesting this relationship – coming from their research and /
or their scientific knowledge
• Give details of their planned procedure – drawing on their experience of the
preliminary work, including the repeatability of the data achieved in it
• Include a risk assessment.
Note that the plan need not be complete at this stage – it can be modified in the light
of experience, e.g. in the light of experience of the repeat results. It is not anticipated
that the plans occupy more than 2 or 3 sides of A4. This stage of the controlled
assessment may take up to 2 hours of formally supervised time.
5.
Data acquisition. This stage of the controlled assessment is carried out under a
limited level of control; candidates with similar plans are allowed to work in groups.
Credit is available in the next phase of the controlled assessment for reporting
decisions made during data acquisition, e.g. modifying the method of fixing the
controlled variables or checking suspect results. It is anticipated that this stage of the
controlled assessment will take up to approximately 2 hours. During this stage,
feedback should be limited to clarification of the requirements of the assessment.
6.
Report writing. This stage of the controlled assessment is carried out under a high
level of control, i.e. the candidates work individually. The candidates present their
data appropriately, e.g. using tables, charts and graphs, chosen to allow the
hypothesis to be tested as rigorously as possible. Any decisions made during data
acquisition, including modifications to the plan should be presented with justification.
The report should include suitable analysis of the data and a conclusion relating to
the hypothesis. The extent and quality of the data should be explored alongside a
discussion on the degree of confidence in the conclusion.
This stage of the controlled assessment may take up to 3 hours. The extent of the
report, including tables and graphs, should occupy not more than 4 sides of A4.
During this stage, feedback should be limited to clarification of the requirements of
the assessment.
7.
Assessment. This stage of the controlled assessment is carried out under a
medium level of control. Supervisors use the WJEC marking criteria to assess the
report using a "best fit" approach.
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 191
Controlled Assessment
Additional Science: Investigation
Marking Criteria
1.
The work of each candidate should be assessed in each of the following fields
1.
2.
3.
4.
Hypothesising and planning
Collecting, reviewing and processing data
Analysing and reviewing procedure
Analysing data and concluding
2.
The maximum mark in each assessment field is 12 and is subdivided into the
following bands:
0 marks, 1 – 3 marks, 4 – 6 marks, 7 – 9 marks, 10 – 12 marks
3.
The bands are hierarchical; however, a "best fit" approach should be adopted, i.e.
minor shortcomings at one level can be overcome by a candidate clearly meeting the
additional demands of a higher level.
4.
The demands of quality of written communication are incorporated into the criteria in
fields 2 and 4.
5.
Centres are required to annotate work to show which level is achieved in each field
and to indicate the evidence for the achievement of the level and position within the
level.
6.
The marks for each of the fields should be entered into the table on the controlled
assessment cover sheet and the authenticating declarations by the candidate and
teacher / lecturer signed and dated.
7.
A single mark out of 48 is submitted.
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 192
Hypothesising and planning
Mark
range
0
1-3
4-6
Description
Exemplification – indicative assessment points
No evidence of planning is
presented.
Candidates work from a given
hypothesis and make a plan to
collect some relevant data without
necessarily controlling variables.
They take some account of safety in
their plan.
Working perhaps from a given simple hypothesis, e.g. heavier objects take a shorter time
to reach the floor, the candidates plan to do some or all of:
• time an object (e.g. 1 or more cake cases) to fall from a height to the floor
• time a heavier object to fall from a height (not necessarily the same height) to the
floor
• repeat a reading at least once
• work safely, e.g. mention a normal laboratory rule
Candidates make a simple
hypothesis relating the independent
and dependent variables. Plan
identifies independent and
dependent variables without
necessarily identifying controlled
variables explicitly. They identify
any significant hazards relating to
the investigation.
Candidates make a simple qualitative hypothesis, e.g. the heavier the object the faster it
falls or the heavier the object the shorter the time it takes to reach the ground. The
following points for credit relate to these hypotheses but candidates may use other
independent variables e.g. surface area [size] of object
Candidates
• identify by implication the mass / weight of an object and the time to reach the ground
/ [terminal] speed of falling as the variables to investigate
• plan to measure descent from the same height if hypothesis expressed in terms of
time or to allow object to reach terminal velocity
• plan to make timings for different masses
• plan to repeat timings at least once
• identify a hazard or make a case that there are no significant hazards
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 193
Hypothesising and planning
Mark
range
7-9
10-12
Description
Exemplification – indicative assessment points
Candidates make a hypothesis
relating the variables to be
investigated and discuss it in terms
of scientific knowledge or the results
of their preliminary research. Plan
identifies the variables which need to
be controlled and includes ranges
and intervals of variables and
appropriate numbers of repeats.
They use the experience of previous
work to produce a simple risk
assessment for the investigation.
In addition to the above, candidates
• identify explicitly all significant variables, mass of object, size / area of object, shape of
object, terminal velocity [NB the hypothesis should be framed in terms of the terminal
velocity and not the time to reach the ground]
• identify clearly the variables which need to be controlled [size / area and shape for the
above hypothesis and drop height if time, rather than terminal velocity is the
dependent variable]
• relate the hypothesis qualitatively to concepts of drag / air resistance, weight and
resultant force or justify it in terms of experience of the preliminary work or research,
including secondary data
• plan a range and intervals of the independent variable which should lead to a test of
the hypothesis [maximum value at least 4 times the minimum value and at least 5
different and reasonably spaced values]
• plan to allow the falling object to reach terminal velocity before making measurements
• plan to take at least three readings at each value of the independent variable – or
justify why fewer are sufficient, e.g. from the preliminary work
• produce a simple risk assessment for the investigation
Candidates additionally justify the
need to control specific variables in
terms of a valid investigation or
discuss the limitations of the
investigation where variables cannot
be controlled. They use the results
of scientific knowledge, preliminary
work and research to make a
hypothesis. They use the results of
preliminary work to inform details of
the plan, e.g. in terms of ranges and
number of repeats.
In addition to the above, candidates
• use their scientific knowledge of forces and motion to explain why named variables
need to be controlled
• use the results of research to make a quantitative hypothesis, e.g. within the model
that drag is given by kAv2, predict the relationship between terminal velocity and mass
or area
• indicate how they will test the hypothesis, i.e. what graph they will plot and how they
will judge to what extent the hypothesis is supported by the data
• use the details of the preliminary work, including secondary data, to justify the number
of repeat readings required [in terms of the expected scatter of the individual readings]
and the distance required to reach terminal velocity
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 194
Collecting, reviewing and processing data
Mark
range
0
Description
No evidence of data collection is
presented.
Candidates work safely, collect data
relevant to the investigation and
display collected data.
Working with due regard for safety, candidates
• make a single relevant measurement of the dependent variable for one value of the
independent variable
• measure the dependent variable for at least two different values of the independent
variable, without necessarily controlling other variables
• present the measured values of dependent and independent variables – not
necessarily in systematic form or with correct use of units
Candidates collect sufficient
relevant data which enables an
initial assessment of the validity of
the hypothesis to inform the plan.
They select simple forms and styles
of presentation of the data including
a simple table, graph, chart or
diagram which enables data to be
interpreted; they process some
data mathematically, e.g. by
averaging.
In addition to the above, candidates
• make measurements of the dependent variable for at least 3 widely spread values of
the independent variable
• repeat a measurement of the dependent variable for at least one value of the
independent variable
• make enough measurements of the dependent variable to enable the supervisor to
make an initial judgement of the validity of the hypothesis
• determine the mean value of the dependent variable, which could be the time of
descent rather than terminal velocity, for at least 3 values of the independent variable
• produce a table of results for at least 3 values of the independent variable, not
necessarily including repeated readings of the dependent variable for all values of the
independent variable
• produce of graph of the dependent against the independent variable, which could be
time of descent rather than terminal velocity
1-3
4-6
Exemplification – indicative assessment points
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 195
Collecting, reviewing and processing data
Mark
range
Description
Exemplification – indicative assessment points
7-9
Candidates collect sufficient valid
data which enables them to make a
judgement on a simple hypothesis
and review details of the plan in the
light of results. Using standard
forms and styles of presentation
appropriate to the task, they display
data systematically, including
detailed graph or chart; they use
judgement in the selection and
mathematical processing of data
which they display appropriately.
Candidates
• control all relevant variables and ensure that terminal velocity is achieved
• they determine the terminal velocity from their time measurement
• collect data from at least 5 widely spread values of the independent variable
sufficient to allow a judgement on a qualitative hypothesis, which should be in
terms of terminal velocity
• display data, with units, in appropriate sequence in a table or tables
• average, ignoring suspect values if appropriate
• produce of graph of the terminal velocity against the independent variable with
good choice of scales and well labelled axes
• comment on any changes to the details of the plan, e.g. number of repeats, in the
light of experience
10-12
Candidates collect sufficient highquality valid data which enables
them to make a good judgement of
a detailed hypothesis and they
discuss the sufficiency of the data,
reflecting upon the plan. They select
and effectively use high level forms
and styles of presentation
appropriate to the task; they
process data appropriately and
accurately producing a high-level
display of the data.
Candidates
• produce data that are sufficient [in terms of spread of independent variable values
and variability of dependent variable values] to test a quantitative hypothesis
• produce a clear table or tables of results and appropriately manipulated values,
e.g. values of v2 or √m , with appropriate units
• produce a graph, with good choice of scales and clearly labelled axes, which can
be used to test quantitative hypothesis, e.g. v2 against m
• consider the sufficiency of the data
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 196
Analysing and reviewing procedure
Mark
range
0
1-3
4-6
7-9
Description
Exemplification – indicative assessment points
No evidence of analysis or
reviewing presented.
Candidates make simple comments
about techniques in the procedure
and on the quality of the evidence
produced. They make a simple
statement referring to other data,
e.g. in the preliminary work or
research.
To be awarded credit, candidates,
•
•
•
make a low level statement about how the procedure was carried out, e.g. the
difficulty of timing, e.g. it was difficult to time it accurately
make a low level statement about how accurate they think the data are
statements are brief and non-qualified
Candidates make detailed, relevant
comments about techniques in the
procedure and use the spread/trend
of their raw data to comment on the
repeatability of the data produced.
They make a detailed statement
referring to other data, e.g. in the
preliminary work or research.
Candidates
• make more detailed statements, e.g. it was difficult to time it accurately because the
cake cases fell so fast
• make a statement referring to control variables
• make a statement which refers to how spread out the data were, either the plotted
mean points or the individual readings for a particular value of the dependent variable
• comment on how close different groups' results were in the preliminary work or how
the relationship fits in with their research
Candidates suggest changes to the
techniques in the procedure.
They justify improvements in terms
of the repeatability of the
measurements or justify an
assertion that no improvement is
necessary. They comment on other
data, e.g. in the preliminary work or
research.
Candidates
• suggest a way of improving the evidence or show why the evidence does not need
improvement, e.g. using light gates [to improve accuracy] or the pattern in the graph is
clear and all the points lie on a smooth line [more evidence not needed]
• make a statement indicating the extent to which it was possible to control variables,
e.g. the surface area of the cake cases was controlled well but sometimes there were
air draughts which could have affected the results
• comment on how this investigation supports or contradicts the preliminary work and /
or the research, referring to the results of different groups
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 197
Analysing and reviewing procedure
Mark
range
10-12
Description
Candidates discuss the limitations
of the investigation. They relate the
outcome of the investigation with
information discovered in the
candidate's research, making a
detailed comparison.
Exemplification – indicative assessment points
Candidates, additionally,
• examine the repeatability and/or reproducibility [from the preliminary work] and
discuss to what extent the data support the conclusion
• justify in detail the control of variables, e.g. the confidence that terminal velocity had
been reached, or the difficulty of doing this.
• discuss in detail to what extent the data are in line with the initial research
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 198
Analysing data and concluding
Mark
range
0
1-3
4-6
Description
Exemplification – indicative assessment points
No relevant analysis or conclusion
presented.
Candidates make a simple, relevant
statement about the data, possibly
identifying some trends or patterns
in the data. The presentation may
have major inaccuracies of spelling,
punctuation and grammar; little use
of scientific vocabulary
To be awarded credit, candidates,
• may analyse data and review using unscientific terms, lack of units, in incomplete
sentences and in a way which requires the assessor to search for relevant points
• make a correct statement referring to the data which may be about one value of the
dependent variable, e.g. one cake case took *** seconds to fall
• make a correct statement referring to at least two values of the dependent variable
without necessarily referring to a trend
Candidates
Candidates give a detailed,
accurate description of the trends or • analyse data and review using basic scientific terms, express quantities with their
patterns in the data relating the
units and write in simple sentences which may not be accurately constructed
trends to information discovered in
• make a simple statement linking the variation of the dependent variable varies with
the candidate's research. The
that of the independent variable, e.g. the greater the mass [or the greater the number
presentation has inaccuracies in
of cake cases] the higher the terminal velocity [or the quicker (sic) it falls]
spelling, punctuation and grammar;
use of scientific vocabulary is
limited.
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 199
Analysing data and concluding
Mark
range
7-9
10-12
Description
Exemplification – indicative assessment points
Candidates identify the
relationship(s) between variables
revealed in the data, relating this to
the hypothesis. They make a
comparison of the outcome of the
investigation with information
discovered in the candidate's
research. The presentation has no
major inaccuracies in spelling,
punctuation and grammar; use of
scientific vocabulary is good.
Candidates
• analyse data and review using basic scientific terms, express quantities with their
units and write in simple sentences with no major inaccuracies in construction
• make a qualitative but detailed statement linking the variables, e.g. the heavier the
object, the greater the terminal velocity , but the velocity is not proportional to the
mass – as the mass increases the increase in velocity becomes less
• comment on the extent to which the relationship supports the hypothesis
• comment on how this investigation supports or contradicts the research
Candidates produce a valid
conclusion from the data collected.
They discuss the extent to which the
data support the hypothesis
(including whether an alternative
hypothesis is supported). They
discuss the extent to which
more/improved quality of the data
would improve their confidence in
the conclusion. The presentation
has good spelling, punctuation and
grammar; use of scientific
vocabulary is appropriate and of a
high standard.
Candidates, additionally,
• analyse data and review in scientific terms, express quantities with their units and
write accurately in clear sentences
• make a quantitative conclusion relating the independent and dependent variable, or
show that the expected quantitative relationship is not supported by the data, e.g. I
expected the terminal velocity to be proportional to the square root of the mass but it
wasn't because…..
• consider whether a different conclusion is also supported by the data, e.g. it looks as
though the terminal velocity is proportional to the square root of the mass but the
scatter of the points means that the terminal velocity and mass might be proportional
[with backing up]
• discuss in detail to what extent the data are in line with the initial research
GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 201
MARK SPECIFICATION GRID
GCSE Additional Science
Controlled Assessment
Assessment Objective
As percentage of the controlled
assessment
Marks for the controlled
assessment
AO1
AO2
AO3
Total
Mark
HSW
QWC
18.75%
25%
56.25%
100%
3
3
9
12
27
48
WJEC GCSE in Additional Science SAMs - 2011/ED
15/02/2011