Steps to the Scientific Method Continued
In the previous lesson, we started discussing about the scientific method, we looked at five steps to the scientific method: the question, introduction, identifying variables, hypothesis and aim. In this lesson, we will continue from the sixth step.
All the apparatus that you will need for the investigation needs to be listed.
Sizes of beakers, test tubes and measuring cylinders
Specialised equipment that you may need must also be included (make sure that this equipment is available for your research).
Include all chemicals and quantities that are required for your investigation.
The next step is to test your hypothesis. An experiment is a tool that you design to find out if your ideas about your question are right or wrong. You must design an experiment that accurately tests your hypothesis. The experiment is the most important part of the scientific method. We will discuss independent and dependent variables as well as controls later. These are all important concepts to know when designing an experiment. In science, another researcher may want to repeat your method, to verify your results, improve it or do a variation of your experiment. Listing the apparatus helps others to verify that you used a suitable method, and enables them to replicate the experiment.
Write down the scientific method in bullet format for your investigation.
The method should be written so that a complete stranger will be able to carry out the same procedure in the exact same way and get almost identical results.
The method should be written in the past tense using the passive voice.
The method must be clear and precise instructions including
- the apparatus
- exact measurements or quantities of chemicals or substances
Ensure that your method is written out in the correct sequence, with each step of the experiment numbered.
State the criteria you will look for or measure to get results.
Give clear instructions how the results should be recorded (table, graph etc.)
Include safety precautions where possible.
- Record your observations from doing the investigation.
It is important that you do not write out an explanation for the results.
Present your results in a suitable format such as tables and graphs.
It is also important to note that not getting the result you expected is still a result. Even if there is no change at all, this is still a result that needs to be recorded.
9. Analysis of results or Discussion
The analysis of the results is stating in words what the results are often saying in tables/graphs.
Discuss if there are there any relationships between your independent and dependent variables.
It is important to look for patterns/trends in your graphs or tables and describe these clearly in words.
10. Evaluation of results
This is where you answer the question “What do the results mean?”
You need to carefully consider the results:
- Were there any unusual results? If so then these should be discussed and possible reasons for them can be given.
Discuss how you ensured the validity and reliability of the investigation.
Validity: Was it a fair test and did it test what it set out to test?
Reliability: If the experiment were to be repeated would the results obtained be similar?
The best way to ensure reliability is to repeat the experiment several times and obtain an average.
Discuss any experimental errors that may have occurred during the experiment. These can include errors in the methods and apparatus used and what make suggestions what could be done differently next time.
The conclusion needs to link the results to the aim and hypothesis. In a short paragraph, write down if what was observed is supported or rejected by the hypothesis by restating the variables that were tested. If your original hypothesis does not match up with the final results of your experiment, do not change the hypothesis. Instead, try and explain what might have been wrong with your original hypothesis. What information did you not have originally that cause you to be wrong in your prediction.
Example: after conducting your experiment you may have found that tomato plants that received more sunlight grew larger than tomato plants grown in the shade or without light. Therefore you might conclude your investigation with the following:
- It was clear that tomato plants form bigger tomatoes when they are exposed to bright sunlight. The original hypothesis was supported.