2. Learning Objectives
:
• Identify variables in a practical
all
• .
• Decide on which variables to
most change, measure and keep the same
• Know the correct terms for
some variables
3. Revision of variables
Can you
…an
remember
…a
what is control
…a meant
independent
dependent
variable?
by…
variable?
variable?
4. Revision of variables Summary:
The independent variable
is the one that you change or select.
The dependent variable
is the one changes as a result,
and that you measure.
The control variables must not change,
so that it is a fair test.
5. In summary
• Categoric
These have word labels.
• Ordered
These categoric variables can be ranked,
in an order.
• Discrete
These can only have whole number values.
• Continuous
These can have any numerical value.
6. Planning
• When we plan an experiment we must always
make sure that we choose a
• suitable range
• and
• number of values for the independent variable.
7. Range
• It is important in science to choose the correct
range of Independent Variable.
• E.g. the age of pupils in our school range from
11 18.
8. Fair Testing Assessment
• A car manufacturer wanted to test
the braking distances of its cars at
different speeds.
• What would you say the following
should be? There is more
information on the following slide
– Independent Variable –
– Dependent Variable –
– Control Variables –
– Range of Independent Variable-
– Values of Independent Variable –
9. Fair Testing Assessment
Braking distances and speed.
• Independent Variable
– What am I changing in this investigation?
• Dependent Variable
– Because of what I am changing, what will I measure?
• Control Variables
– To make it a fair test what do I need to keep the same.
• Control Variables – Ones I cannot Control
– Which things will it be difficult to control?
• Range of Independent Variable
• Values of Independent Variable
10. Plenary
• Use the post-it to mark which plan is the best
• Write on it what you like about it
