This article will begin the series of “what is science?” by introducing the foundation of science and experimentation: the scientific method. Experiments are what allow scientists to uncover truths about the world. The rise of experimentation in science began in the 16th century and was primarily mathematical and physics-based. However, in the 19th century, this extended towards other sciences such as medicine and psychology.
The process of experimental science begins with the hypothesis. Think of a hypothesis as an educated guess. First one may make an observation about the world, maybe they notice that plants that do not get much sunlight do not grow as well. It may therefore be hypothesized that plants require sunlight to grow. An experiment may subsequently be designed in order to test this hypothesis. However, contrary to what you may have learnt in school, there are several forms of a hypothesis. I will be describing the two most commonly used hypotheses: the null and alternate hypothesis. Coming back to the question as to whether plants require sunlight to grow, the null hypothesis will state that there is no relationship between sunlight and plant growth. Conversely, the alternate hypothesis will state that there is indeed a relationship. Once the null and alternate hypotheses have been established, next comes the experimental design.
Experiments often contain many variables. Two of the most common variables are the independent and dependent variables. The independent variables are ones that are changed or controlled by the researcher. For example, if one is testing whether plants require sunlight for growth, the independent variable may be sunlight itself or perhaps an artificial light. Independent variables are not the ones being measured by the researcher. In contrast, the dependent variable is being measured. Essentially, these variables are dependent on the independent variable chosen and will, therefore, change. For example, Plant growth may change as a result of exposure to sunlight or artificial lights and is therefore the dependent variable.
You can’t have an experiment without a control. A control is a variable in an experiment that remains constant and unchanged. The dependent variable, which is the one that scientists are interested in measuring, is often compared to the control to determine whether these changes were due to the independent variable or perhaps something else affecting the experimental outcome. For example, the plant that is treated with sunlight is compared to the plant that is not treated in order to determine whether plant growth was due to sunlight. However, there are several forms of controls. For example, imagine I was running a different experiment, say whether injecting insulin into a patient increases glucose uptake. If the insulin was dissolved in saline water, I could use the solution by itself to determine that the effects weren’t because of the saline water. This is called a vehicle control.
Once the results of the experiment is obtained, one may the analyze them and form a conclusion. This may then generate further hypotheses down the line, until a theory is then formed. For example, if it is found that sunlight is required for plant grown, a hypothesis can then be generated to explain why this happens. It turns out, this has already been done and we now know that sunlight allows plants to synthesize sugars through photosynthesis. We also know how plants use sunlight for this process. One simple educated guess has generated an entire theory explaining processes in the natural world.
To end this article, it is important to note that scientific articles typically don’t include this language. This is due to the fact that every researchers has been taught the scientific method. As such, there’s no reason to waste time writing your hypothesis or listing the types of variables because it is common knowledge in the research community. This is why I am writing this article, because understanding the scientific method, including how simple experiments are designed, is key to understanding scientific concepts.
