Asking Scientific Questions and Planning Enquiries

• Ask relevant questions
• Plan and set up scientific enquiries
• Recognise and control variables, and ensure a fair test

Asking the Question
Most enquiries in science start with a question that is designed to help something be even better understood. Finding the answer is the aim of the enquiry.
For example, if a scientist already knows that germination of a seed is the start of most plant growth, this knowledge could lead to the following question:

Careful thought is needed about exactly what the question is asking. The enquiry could investigate everything a seed might need in order to grow, but that would be a much larger task. It is also important to use correct vocabulary – plants grow but seeds germinate.

Planning a Scientific Enquiry
The next step is to plan how to investigate the question. This is known as the method of the enquiry – what will be done to try to find the answer to the question.
The equipment to be used will need thinking about, as well as how to measure the outcomes. For example, seeds, water and a dish to put them in will be needed, and the outcome could be measured by observing the seeds.
The seeds could be placed on cotton wool in a dish. Some cress seeds (which germinate relatively quickly) could be placed on wet cotton wool, and others on dry cotton wool.

Controlling Variables
When planning the method of enquiry, consideration must be given to the things that could affect the outcome. These are known as variables. Could any of these play a part in the seed germination enquiry?

Creating a Fair Test
In a fair test, only the variable being tested is changed.

Example
To make sure that the seed germination is a fair test:
• each dish should be placed in the same location at the same time
• the dishes should be exactly the same size
• the type and amount of cotton wool should be the same
• the type and number of cress seeds should also be the same.
The only variable which changes is the presence of water. The cotton wool in one dish should be dry and in the other dish, wet.

Quick Test

1. Question:

What does a scientific enquiry begin with?

2. Question:

Which step in planning an enquiry deals with how it will be done?

3. Question:

What is meant by the term ‘fair test’?

Collecting and Recording Data

• Make systematic and careful observations
• Take accurate measurements using appropriate equipment and methods
• Use standard units when recording data

Taking Measurements
Always consider exactly what should be measured. This will help in choosing the correct equipment and the correct unit of measure.

If measuring how much some plant shoots grow in a certain number of days following germination, a ruler is needed to measure in centimetres or millimetres. It is also useful to provide more information, for example how many seeds germinated.
If measuring the change in temperature of the contents of a beaker of snow when left in the classroom for a day, careful observation, a thermometer and a clock or watch will be required.

If measuring temperature change over time, for example, when testing the insulating properties of a material, a thermometer and stopwatch, or a data logger, are needed.
The correct units should be chosen and used when measuring, for example:

Accuracy in observations and measurement should be ensured.

Observing and Recording Data
Once data has been collected, a little more thought is needed before any answer is given to the question posed by the enquiry.
Repetition helps check the reliability of data. To be more certain about data, the investigation should be repeated (more than once ideally) in case there were other factors
affecting the investigation.
Recording of observations and measurements should be systematic and in a simple form. Using a table helps to keep data clear and organised.
This table shows how the temperature of the contents of a beaker, initially full of snow, changed over the course of a day in the classroom.

It was essential that the temperature was measured every hour.
Here is a table showing the amount of water that evaporated in 24 hours from beakers in different locations around the home.

Careful measurements of the amount of water remaining in each beaker were taken at the end of the 24-hour period, allowing a calculation of how much water had evaporated.

Quick Test

1. Question:

For the evaporation enquiry above, name two variables that must be kept the same.

2. Question:

Using the table above, in which location did most evaporation occur?

3. Question:

Why should an enquiry be repeated with several samples?

Making Conclusions

• Present findings from enquiries
• Report on findings from enquiries
• Draw conclusions from data

Presenting Findings
Using tables to record data can help to:
• keep data organised
• spot patterns in the data.
Look at the first table on page 7. If the original question was How does the temperature of the contents of a beaker, initially filled with snow, change during a day in the
classroom? then it can be seen that the temperature rises throughout the day. This can also be shown as a graph:

This line graph really helps to show the change in temperature over time.
From the second table on page 7, it is possible to work out where the water evaporated most, but this can be made more visual by use of a bar chart. If the original question
was, How does evaporation of water differ in different indoor locations? it can be seen from the table, and more clearly from the bar chart, that more water evaporates in
the airing cupboard than in the other locations.

Reporting Findings and Drawing Conclusions
It is one thing to record and present data from an enquiry, but quite another to then draw useful conclusions.
A simple conclusion from the snow enquiry would be that the temperature of the snow rises in the classroom. This is true, but could have been guessed without going to the effort of putting the snow in a beaker and recording the temperature each hour. When looking at the data, the question of how the temperature changes needs to be answered.
Looking at the line on the graph, it can be seen that it starts quite steep before becoming less steep. This helps in drawing the simple conclusion that temperature rises as time passes.
However, it also allows the conclusion that the temperature in the beaker rises quickly to begin with before slowing down.
Reporting all of this requires the data to be presented (using the line graph) alongside a written conclusion. The conclusion could simply state:

Looking at the data from the evaporation enquiry, an assumption has to be made when drawing the conclusion – the freezer is clearly the coldest place in the house and,
in most homes, an airing cupboard will be the warmest. The simple conclusion for this enquiry is that:

As with all scientific enquiries though, conclusions often lead to further questions, as can be seen in the next section.

Quick Test

1. Question:

Why is a chart such as a graph or bar chart useful for presenting data?

2. Question:

How would you present data showing change over time?

3. Question:

What is the purpose of the conclusion to an enquiry?

Using Evidence and Improving Enquiries

• Use evidence to answer questions
• Identify evidence that has been used to support or refute ideas or arguments

Identifying and Using Evidence
The question asked earlier for the germination enquiry was: Is water required for germination? If the seeds with water germinated, and those without water did not, this
can be used as evidence that water is required for the germination of cress seeds.
It is important to identify and refer to the evidence being used to answer the enquiry question. However, there also needs to be confidence in the evidence. The enquiry could be repeated, and evidence can be discussed in terms of the percentage of seeds germinating, and amount of water used. When answering the question, it is important to ask whether this evidence is good enough to be able to give a confident answer.

Improving the Enquiry
When looking at evidence also think of ways to improve the enquiry. Consider if anything could have been done differently, such as using different equipment or making
the test more reliable. It may be that the enquiry is then repeated with any changes made. Evidence from an enquiry can also be used to lead to further questions and
enquiries to deepen scientific knowledge. For example:

Quick Test

1. Question:

Why is it important to be confident in the evidence used?

2. Question:

Why might an enquiry sometimes need to be done again?

Practice Questions

Challenge 1

1 Question:

What equipment would you need to measure the temperature of water?

2 Question:

What is the ‘method’ of an enquiry?

3 Question:

Why might you record data in a table?

Challenge 2

1 Question:

You are asked to measure how quickly boiling water cools in different- shaped containers. What equipment would you need?

2 Question:

How would you ensure this is a fair test?

Challenge 3

1 Question:

The table below shows the size of bean plants after being left to grow in different places for two weeks.

Assuming all variables were the same apart from the location, what can you conclude from this data?

2 Question:

How could the reliability of the data above be improved?