Working like a scientist
What’s the question?
Scientific question can be answered through
experiment, observation, or other data collection.
Scientific question is clear and specific, and it helps
us learn about how things work in the natural world.
For example, “What happens to a plant if it doesn’t
get any water?”
Some are questions that science can answer.
• Why does the battery last longer in some mobile phones than
others?
• How has air pollution in London changed over time?
• What happens to a balloon when you put it in the freezer?
• What happens if you mix vinegar and baking soda?
• Does the amount of salt in water affect how quickly an egg
floats?
• Does the temperature of water affect how fast sugar dissolves?
• What type of surface makes a toy car roll the farthest?
Suggesting ideas
An observation can give you an idea for a scientific
question.
For example: Tom and Katie are watching a tennis
match. Tom notices that tennis balls bounce much
higher than footballs. They also notice that new tennis
balls are brought out from a refrigerator during the
tennis match. Katie makes an observation about the
tennis balls. She identifies the key features and uses
scientific language.
Developing ideas into questions
Here are some questions that Katie and Tom
might investigate:
● How does the height of the bounce change
over time?
● How does the temperature of a ball affect how
high it bounces?
A good scientific question involves two variables:
Independent variable
Dependent variable
What is variable?
In science, anything that can change during an
investigation, such as the temperature, is called a
variable. The thing that is affected as a result of
the change is also a variable.
Independent variable: a variable whose variation does
not depend on that of another.
For example: The temperature is the independent
variable. It is independent because you change it to
see how it affects another variable.
Dependent variable: a variable whose variation
depends on that of another.
For example: How high the ball bounces is the
dependent variable. It is dependent because it
changes when you change the temperature.
Control variables: Katie and Tom need to keep these
variables the same during their investigation so that
they do not affect the bounce height. These are called
control variables.
Here is their list:
● the height you drop the ball from
● the type of ball
● the surface that you drop the ball onto
● the diameter of the ball
Types of scientific enquiry questions
We can use 5 different types of scientific enquiry to find answers
to different kinds of science questions.
1. Research
Sometimes we cannot find the answer to a scientific question in a
direct way, such as by doing an investigation or by speaking to
people. Instead, we can do research to find the information we
are looking for by reading books, using the internet or watching
videos. These are all known as secondary sources of information.
For example:
find out about new scientific discoveries or
discoveries made in the past, for example the
discovery of magnetism.
find images, such as examples of Earth
features, that satellites in space photograph
and send back to scientists on Earth.
enquiry.
Changing only one variable to examine
the effect on another variable makes the
investigation a fair test.
A fair test is a way of doing an
experiment where you make sure that
everything stays the same except for one
thing you want to test. This helps you
Example:
If you want to see if plants grow better with more sunlight,
you’d:
•Use the same type of plant, soil, and pot. ( control )
•Give each plant a different amount of sunlight, but keep
everything else the same. ( independent)
•Measure how much the plants grow to see if more sunlight
helps them grow better. (dependent)
This way, you know that any difference in plant growth is due
to the sunlight, not other factors.
For example, in Unit 2 when we investigate
which material muffles sound best, the control
variable is the source of sound because we
keep this the same. The independent variable
is the muffling material because we change
this from newspaper to bubble wrap to a
blanket. The dependent variable is the sound
volume we measure, because this changes
according to which muffling material we use.
3. Observation enquiry questions :
In investigations we often need to observe changes
caused by things we do.
For example, what happens to water when we freeze it,
or what happens when we mix sugar and water?
For example, ‘How are the young of mammals different
from each other?’
How does the volume of gas produced in a chemical
reaction change over time?
How often we need to observe depends on the changes we are
looking at.
We can see some changes straight away, such as the change in
colour of iodine solution when starch is present.
If we observe what happens when we mix sugar and water, we
can see the change in a few minutes.
The changes to water when it freezes will take a few hours to
observe. Observing changes in nature can often take longer.
When we investigate what happens when a seed germinates, we
will need to observe changes over days or weeks, depending on
the type of seed. We will need a whole year to observe the
changes that happen as the seasons change.
4. Identifying and classifying
Identifying is the process of naming something, for example an apple
or an orange. We can name them because they have features we
recognise.
Classifying is organising things into groups. We classify objects,
materials and living things in groups by looking at the ways in which
they are similar or different.
We can usually classify these things by asking a series of 'yes or no'
questions. For example, does a flower have brightly coloured petals?
Does the flower have a scent?
The answers to these questions will help us decide if the flower is
pollinated by insects or wind.
Pattern seeking
Pattern seeking involves observing, recording and analysing
data.
The patterns we observe can help us to identify a trend or
relationships between one or more things. We often find
patterns in nature where we cannot easily control the variables.
For example:
• a pattern in the relationship between seed size and the time
it takes a seed to germinate
• a pattern in the type of material that sound travels through
best.
Imagine you are a student recording the daily high
temperatures in your city for a month. You’re trying to
find out if there’s a pattern in the temperature changes.
1.Collect Data: For each day of the month, you write
down the high temperature.
2.Analyze Data: At the end of the month, you look at
the list of temperatures and notice that the temperatures
tend to rise steadily as the month progresses.
3.Identify Pattern: You see that the temperatures
increase every few days and that the highest
4. Pattern seeking enquiry
questions, including:
Correlations: A correlation means
that B changes when A changes,
but it does not necessarily mean
that the change to A causes the
change to B.
For example, ‘Is there a correlation
between drinking fizzy drinks and
getting good test marks?’
KEY TERMS
Observation,
Scientific enquiry,
Data,
Investigation,
Variable,
Independent variable,
Dependent variable,
Control variable,
Fair test,
Observation enquiry,
Pattern seeking
enquiry,
Correlation,