WInSTEP Environmental Health Science Program: Scientific Method

This introduction to the scientific method provides a background of how scientists learn about the physical world.

Research in the natural sciences aims to understand the physics, geology, chemistry, and biology of planet Earth, the solar system, and beyond. The success of this bold mission depends on basic assumptions about how the universe works and ways of learning about any part of it through the application of the scientific method. Here we consider foundational beliefs that scientists hold in order to be able to study and comprehend nature.

Science seeks to understand nature using its own special brand of critical thinking called the scientific method. Scientists believe that the goal of their studies is objective truth that would be discovered no matter who is doing the research as long as they use this method. The unique feature of science is its focus on doing experiments that generate new data and new information beyond what is currently known, leading to new knowledge.

How do students become interested in science and develop into professional scientists? How do scientists decide on specific problems or questions to investigate? General areas of research are often determined by interests that develop during their education.

The diagram of the flexible scientific method from section 2 can be divided into two parts as a starting point for understanding the role of hypothesis in doing science. The first involves choosing a research question, developing a hypothesis that provides a possible answer to the question, and designing experiments that evaluate whether predictions derived from the hypothesis are factually true. The second part carries out the planned experiments, collects observations or data, and then searches the data for recognizable patterns of cause and effect that indicate whether the predictions are correct and, therefore, that the hypothesis is consistent with the facts of nature. Patterns are commonly called “information.”

How are experiments devised that yield reproducible data and are likely to rigorously test whether the hypothesis is correct? Experimental design starts with a prediction from the starting hypothesis and proceeds to envision an experiment that tests the hypothesis.

Doing experiments and making careful observations of nature are what distinguish science from other ways of knowing. It follows that the whole scientific process depends on the quality of such experiments and observations. The primary judge of the quality of experiments is reproducibility.

At the core of the method are experiments that generate observations or data. Upon casual review, data, standing alone in a data set, are unlikely to reveal much if any informational content. Instead, they need to be converted into understandable information through data analysis.

This essay will help students understand how the scientific method was applied by various scientists during their work leading to the determination of the structure of DNA.