Writing a scientific procedure

Print What is the Scientific Method?

Writing a scientific procedure

The first step is to write the procedure. The procedure is a set of very specific instruction about how you are going to conduct your experiment. Consider the image below. What happened to the sandwich on the left? Sadly, no one could eat the sandwich on the left. The problem is a lack of detail.

If you have never made a peanut butter and jelly sandwich, the very precise and detailed directions on the right would be necessary to make the sandwich correctly. Details are the most important part of any experiment because without detail, it would be nearly impossible for someone else to replicate your experiment.

Variables Details also help to control variables in your experiment. Before you can begin writing the procedure, you need to decide on your independent variable.

There are three types of variables to consider: Independent Variable The independent variable is the one that YOU choose to help you answer your question. A well designed experiment has only one independent variable. That means you can only change one condition in each experiment. This type of variable is something that you do differently in each trial i.

Nothing else should change but this one variable. Controlled Variables These are all the materials, measurements, and methods that you want to stay exactly the same so that the only thing responsible for change is the independent variable you chose. Every experiment has many controlled variables.

These variables should be exactly the same for every trial i. Dependent Variable The dependent variable is the thing that changes as a result of your independent variable, or the one thing that you intentionally changed.

This is like cause and effect. What happened the dependent variable because of what you changed independent variable? It can be hard to figure out what other conditions must stay the same, but it is important to think it through before you start your experiment.

Look at the image to the right. The student hypothesized that the plant given soda will grow tallest because plants need CO2, and soda has plenty of that!

There are many things this student needs to consider so that the liquid type is the only thing that can affect the growth of the plant. Take some time to think about how this student might write the procedure for this experiment: What are the controlled variables? What details can the student include to make sure these variables are controlled throughout the experiment?

What is the dependent variable?As you will likely recall, the scientific method requires developing a hypothesis, putting it to the test, and then determining if your results support the hypothesis.

Essentially, the format for a research report in the sciences reflects the scientific method but adds to the process a little. If your instructor gives you an outline for how to write a lab report, use that. Some instructors require the lab report be included in a lab notebook, while others will request a separate report.

Here's a format for a lab report you can use if you aren't sure what to write or need an explanation of what to include in the different parts of. Write the experimental procedure like a step-by-step recipe for your science experiment.

A good procedure is so detailed and complete that it lets someone else duplicate your experiment exactly! A good procedure is so detailed and complete that it lets someone else duplicate your experiment exactly! A procedure should be easy to follow. It should have step-by-step directions for conducting the experiment.

writing a scientific procedure

Often it includes a sketch of how to set-up the experiment. The directions may be numbered to be sure they are done in the correct order. Here's an example using the ice cube experiment.

The ability to accurately describe ideas, protocols/procedures, and outcomes are the pillars of scientific writing. Accurate and clear expression of your thoughts and research information should be the primary goal of scientific writing.

12 Remember that accuracy and clarity are even more important when trying to get complicated ideas across. Writing about science is a demanding process. The scientific style of writing has its own rules and guidelines that often differ substantially from how we're taught to write essays in English or history.

How to write the procedure for an experiment