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Things to always include on tasks 1 & 2:
An informative title (describe what the data shows)
Descriptive headings
The units (only one type) in the form "pulse rate /bmp"
First column containing the independent variable (the
thing that is constant)
The time taken for starch to be digested by amylase at
different temperatures.…read more

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Calculations in Data Processing
There are three forms of processing data that depend on what
data is available to when you use them.
1. The mean
This is calculated when more then one repeat has been done.
Calculate the sum of the X values and divide it by the number
of X values there are. It is given by the formula:
2. Rate
This is used when you are comparing the amount produced of
a substance/flow/etc. against time.…read more

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Standard Deviation
This measures the spread of data, and it can only be calculated
when there is more than one repeat.
The larger the standard deviation, the more widely spread the
data is and therefore you have a less reliable mean.
You can compare the standard deviation of two different sets
of data, if the two standard deviation values are far away from
each other and there is no overlap, then the difference is
significant and not due to chance.…read more

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Which Graph to Draw?
Bar Chart
Use this when the controlled variable:
Is non-numerical
Use this when the controlled variable:
Is numerical
Classified into groups
Line Graphs
Use this when the independent and dependent
variable are:
Numerical…read more

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It is used to show relationships that are unapparent from
Use logic to determine which to use, it's usually straightforward.
In scatter diagrams:
The more data points, the more reliable the line of best
fit s
A line of best fit may be drawn if there is an obvious
Scatter diagrams often show correlation. There are generally
three different types.…read more

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When answering questions always state the type of correlation.
If you are evaluating, use the phrase "correlation does not
prove causation, there may be other factors involved for
example...(and give an appropriate example!)."
Never join points by a line of best fit, as you can never be sure
of intermediate values.
Drawing a Graph
There are 6 points you should always include:
1. The independent variable (the one you know) goes on
the x-axis.…read more

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Always put the units and a brief description on the axis
3. Use a suitable scale so more of the graph is used. Use a
line break if necessary.
4. Have equal intervals between all values.
5. DON'T use circles as points; use crosses as they are more
accurate, Only join them together with a ruler, DO NOT
6. ALWAYS give it a highly descriptive title.…read more

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Improves reliability.
A more reliable mean can be
Repeatability calculated.
Anomalies can be identified and
their effect on the mean reduced.
Monitoring a Constantly recording the values of
Variable the variable.
A variable that affects the outcome
that is not the dependent variable.
It should be monitored.
An experiment in which the
dependent variable in changed to
Control Experiment
ensure it is that affecting the
Increasing it improves reliability,
Sample Size as it is representative of the
population.…read more

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Validity ­ Data is valid if the measurements have been made
by a single independent variable only. Controlled experiments
and no bias make results valid.
Repeatability ­ This makes results more reliable.
Accuracy ­ A measurement close to the true value.
Precision ­ Very little spread around the mean value.…read more


Joanna Ly

did you mean independent variable is the thing that changes?


really helpful thanks 

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