How to Write a Scientific Report | Step-by-Step Guide

Is your teacher expecting you to write an experimental report for every class experiment? Are you still unsure about how to write a scientific report properly? Don’t fear! We will guide you through all the parts of a scientific report, step-by-step.

How to write a scientific report:

• What is a scientific report
• General rules to write Scientific reports
• Structure of the scientific report:
  • Title
  • Syllabus dot point 
  • Introduction/Background information
  • Aim
  • Hypothesis
  • Risk assessment
  • Method 
  • Diagram
  • Results
  • Discussion
  • Conclusion

What is a scientific report?

A scientific report documents all aspects of an experimental investigation. This includes:

• A title
• The aim of the experiment
• The hypothesis
• An introduction to the relevant background theory
• The methods used
• The results
• A discussion of the results
• The conclusion

Scientific reports allow their readers to understand the experiment without doing it themselves. In addition, scientific reports give others the opportunity to check the methodology of the experiment to ensure the validity of the results.

A scientific report is written in several stages. We write the introduction, aim, and hypothesis before performing the experiment, record the results during the experiment, and complete the discussion and conclusions after the experiment.

But, before we delve deeper into how to write a scientific report, we need to have a science experiment to write about! Read our 7 Simple Experiments You Can Do At Home article and see which one you want to do.

General rules about writing scientific reports

Learning how to write a scientific report is different from writing English essays or speeches!

You have to use:

• Passive voice (which you should avoid when writing for other subjects like English!)
• Past-tense language
• Headings and subheadings
• A pencil to draw scientific diagrams and graphs
• Simple and clear lines for scientific diagrams
• Tables and graphs where necessary

Structure of scientific reports:

Now that you know the general rules on how to write scientific reports, let’s look at the conventions for their structure!

1. Title

The title should simply introduce what your experiment is about.

Example:

The Role of Light in Photosynthesis

2. Introduction/Background information

Write a paragraph that gives your readers background information to understand your experiment.

This includes explaining scientific theories, processes and other related knowledge.

Example:

Photosynthesis is a vital process for life. It occurs when plants intake carbon dioxide, water, and light, and results in the production of glucose and water. The light required for photosynthesis is absorbed by chlorophyll, the green pigment of plants, which is contained in the chloroplasts.

The glucose produced through photosynthesis is stored as starch, which is used as an energy source for the plant and its consumers.

The presence of starch in the leaves of a plant indicates that photosynthesis has occurred.

3. Aim

The aim identifies what is going to be tested in the experiment. This should be short, concise and clear.

Example

The aim of the experiment is to test whether light is required for photosynthesis to occur.

4. Hypothesis

The hypothesis is a prediction of the outcome of the experiment. You have to use background information to make an educated prediction.

Example

It is predicted that photosynthesis will occur only in leaves that are exposed to light and not in leaves that are not exposed to light. This will be indicated by the presence or absence of starch in the leaves.

5. Risk assessment

Identify the hazards associated with the experiment and provide a method to prevent or minimise the risks. A hazard is something that can cause harm, and the risk is the likelihood that harm will occur from the hazard.

A table is an excellent way to present your risk assessment.

Remember, you have to specify the type of harm that can occur because of the hazard. It is not enough to simply identify the hazard.

• Do not write: “Scissors are sharp”
• Instead, you have to write: “Scissors are sharp and can cause injury”

Example:

6. Method

The method has 3 parts:

1. A list of every material used
2. Steps of what you did in the experiment
3. A scientific diagram of the experimental apparatus

Let’s break down what you need to do for each section.

6a. Materials

This must list every piece of equipment and material you used in the experiment.

Remember, you need to also specify the amount of each material you used.

Example

• 1 geranium plant
• Aluminium foil
• 2 test tubes
• 1 test tube rack
• 1 pair of scissors
• 1 ruler
• 1 250 mL beaker
• 1 pair of forceps
• 1 10 mL measuring cylinder
• Iodine solution (5 mL)
• Methylated spirit (50ml)
• Boiling water
• 1 kettle
• 2 Petri dishes
• 2 labels

6b. Steps

The rule of thumb is that you should write the method in a clear way so that readers are able to repeat the experiment and get similar results.

Using a numbered list for the steps of your experimental procedure is much clearer than writing a whole paragraph of text.  The steps should:

• Be written in a sequential order, based on when they were performed.
• Specify any equipment that was used.
• Specify the quantity of any materials that were used.

You also need to use past tense and passive voice when you are writing your method. Scientific reports are supposed to show the readers what you did in the experiment, not what you will do.

Example

1. Aluminium foil was used to fully cover a leaf of the geranium plant. The plant was left in the sun for three days.
2. On the third day, the covered leaf and 1 non-covered leaf were collected from the plant. The foil was removed from the covered leaf, and a 1 cm square was cut from each leaf using a pair of scissors.
3. 150 mL of water was boiled in a kettle and poured into a 250 mL beaker.
4. Using forceps, the 1 cm square of covered leaf was placed into the beaker of boiling water for 2 minutes. It was then placed in a test tube labelled “dark”.
5. The water in the beaker was discarded and replaced with 150 mL of freshly boiled water.
6. Using forceps, the 1 cm square non-covered leaf was placed into the beaker of boiling water for 2 minutes. It was then placed in a test tube labelled “light”
7. 5 mL of methylated spirit was measured with a measuring cylinder and poured into each test tube so that the leaves were fully covered.
8. The water in the beaker was replaced with 150 mL of freshly boiled water and both the “light” and “dark” test tubes were immersed in the beaker of boiling water for 5 minutes.
9. The leaves were collected from each test tube with forceps, rinsed under cold running water, and placed onto separate labelled Petri dishes.
10. 3 drops of iodine solution were added to each leaf.
11. Both Petri dishes were placed side by side and observations were recorded.
12. The experiment was repeated 5 times, and results were compared between different groups.

6c. Diagram

After you finish your steps, it is time to draw your scientific diagrams! Here are some rules for drawing scientific diagrams:

• Always use a pencil to draw your scientific diagrams.
• Use simple, sharp, 2D lines and shapes to draw your diagram. Don’t draw 3D shapes or use shading.
• Label everything in your diagram.
• Use thin, straight lines to label your diagram. Do not use arrows.
• Ensure that the label lines touch the outline of the equipment you are labelling and not cross over it or stop short of it
• The label lines should never cross over each other.
• Use a ruler for any straight lines in your diagram.
• Draw a sufficiently large diagram so all components can be seen clearly.

Example

7. Results

This is where you document the results of your experiment. The data that you record for your experiment will generally be qualitative and/or quantitative.

Qualitative data is data that relates to qualities and is based on observations (qualitative – quality). This type of data is descriptive and is recorded in words. For example, the colour changed from green to orange, or the liquid became hot.

Quantitative data refers to numerical data (quantitative – quantity). This type of data is recorded using numbers and is either measured or counted. For example, the plant grew 5.2 cm, or there were 5 frogs.

You also need to record your results in an appropriate way. Most of the time, a table is the best way to do this.

Here are some rules to using tables

• Use a pencil and a ruler to draw your table
• Draw neat and straight lines
• Ensure that the table is closed (connect all your lines)
• Don’t cross your lines (erase any lines that stick out of the table)
• Use appropriate columns and rows
• Properly name each column and row (including the units of measurement in brackets)
• Do not write your units in the body of your table (units belong in the header)
• Always include a title

Note: If your results require calculations, clearly write each step.

Example:

Observations of the effects of light on the amount of starch in plant leaves.

If quantitative data was recorded, the data is often also plotted on a graph.

8. Discussion

The discussion is where you analyse and interpret your results, and identify any experimental errors or possible areas of improvements.

You should divide your discussion as follows.

1. Trend in the results

Describe the ‘trend’ in your results. That is, the relationship you observed between your independent and dependent variables.

The independent variable is the variable that you are changing in the experiment. In this experiment, it is the amount of light that the leaves are exposed to.

The dependent variable is the variable that you are measuring in the experiment, In this experiment, it is the presence of starch in the leaves.

Explain how a particular result is achieved by referring to scientific knowledge, theories and any other scientific resources you find.2. Scientific explanation: 

Example:

The presence of starch is indicated when the addition of iodine causes the leaf to turn dark purple. The results show that starch was present in the leaves that were exposed to light, while the leaves that were not exposed to light did not contain starch.

2. Scientific explanation:

Provide an explanation of the results using scientific knowledge, theories and any other scientific resources you find.

Example:

As starch is produced during photosynthesis, these results show that light plays a key role in photosynthesis.

3. Validity 

Validity refers to whether or not your results are valid. This can be done by examining your variables.

VAlidity = VAriables

Identify the independent, dependent, controlled variables and the control experiment (if you have one).

The controlled variables are the variables that you keep the same across all tests e.g. the size of the leaf sample.

The control experiment is where you don’t apply an independent variable. It is untouched for the whole experiment.

Ensure that you never change more than one variable at a time!

Example:

The independent variable of the experiment was amount of light that the leaves were exposed to (the covered and uncovered geranium leaf), while the dependent variable was the presence of starch. The controlled variables were the size of the leaf sample, the duration of the experiment, the amount of time the solutions were heated, and the amount of iodine solution used.

4. Reliability 

Identify how you ensured the reliability of the results.

REliability = REpetition

Show that you repeated your experiments, cross-checked your results with other groups or collated your results with the class.

Example:

The reliability of the results was ensured by repeating the experiment 5 times and comparing results with other groups. Since other groups obtained comparable results, the results are reliable.

5. Accuracy

Accuracy should be discussed if your results are in the form of quantitative data, and there is an accepted value for the result.

Accuracy would not be discussed for our example photosynthesis experiment as qualitative data was collected, however it would if we were measuring gravity using a pendulum:

The measured value of gravity was 9.8 m/s², which is in agreement with the accepted value of 9.8 m/s².

6. Possible improvements 

Identify any errors or risks found in the experiment and provide a method to improve it.

If there are none, then suggest new ways to improve the experimental design, and/or minimise error and risks.

Example:

Possible improvements could be made by including control experiments. For example, testing whether the iodine solution turns dark purple when added to water or methylated spirits. This would help to ensure that the purple colour observed in the experiments is due to the presence of starch in the leaves rather than impurities.

9. Conclusion

State whether the aim was achieved, and if your hypothesis was supported.

Example:

The aim of the investigation was achieved, and it was found that light is required for photosynthesis to occur. This was evidenced by the presence of starch in leaves that had been exposed to light, and the absence of starch in leaves that had been unexposed. These results support the proposed hypothesis.