Scientific Method

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Scientific Method

Whatever the aim of their work, scientists use the same underlying steps to organize their research: (1) they make detailed observations about objects or processes, either as they occur in nature or as they take place during experiments; (2) they collect and analyze the information observed; and (3) they formulate a hypothesis that explains the behavior of the phenomena observed. 

Observation and Experiments

A scientist begins an investigation by observing an object or an activity. Observation typically involves one or more of the human senses—hearing, sight, smell, taste, and touch. Scientists typically use tools to aid in their observations. Scientists typically apply their observation skills to an experiment. An experiment is any kind of trial that enables scientists to control and change at will the conditions under which events occur. It can be something extremely simple, such as heating a solid to see when it melts, or something highly complex, such as bouncing a radio signal off the surface of a distant planet. Scientists typically repeat experiments, sometimes many times, in order to be sure that the results were not affected by unforeseen factors.

Most experiments involve real objects in the physical world, such as electric circuits, chemical compounds, or living organisms. However, with the rapid progress in electronics, computer simulations can now carry out some experiments instead. If they are carefully constructed, these simulations or models can accurately predict how real objects will behave.

Data Collection and Analysis

During an experiment, scientists typically make measurements and collect results as they work. This information, known as data, can take many forms. Data may be a set of numbers, such as daily measurements of the temperature in a particular location or a description of side effects in an animal that has been given an experimental drug. Scientists typically use computers to arrange data in ways that make the information easier to understand and analyze. Data may be arranged into a diagram such as a graph that shows how one quantity (body temperature, for instance) varies in relation to another quantity (days since starting a drug treatment). A scientist flying in a helicopter may collect information about the location of a migrating herd of elephants in Africa during different seasons of a year. The data collected may be in the form of geographic coordinates that can be plotted on a map to provide the position of the elephant herd at any given time during a year.

Scientists use mathematics to analyze the data and help them interpret their results. The types of mathematics used include statistics, which is the analysis of numerical data, and probability, which calculates the likelihood that any particular event will occur.

Formulating the Hypothesis

Once an experiment has been carried out and data collected and analyzed, scientists look for whatever pattern their results produce and try to formulate a hypothesis that explains all the facts observed in an experiment. In developing a hypothesis, scientists employ methods of induction to generalize from the experiment’s results to predict future outcomes, and deduction to infer new facts from experimental results.

Formulating a hypothesis may be difficult for scientists because there may not be enough information provided by a single experiment, or the experiment’s conclusion may not fit old theories. Sometimes scientists do not have any prior idea of a hypothesis before they start their investigations, but often scientists start out with a working hypothesis that will be proved or disproved by the results of the experiment. Scientific hypotheses can be useful, just as hunches and intuition can be useful in everyday life. But they can also be problematic because they tempt scientists, either deliberately or unconsciously, to favor data that support their ideas. Scientists generally take great care to avoid bias, but it remains an ever-present threat. Throughout the history of science, numerous researchers have fallen into this trap, either in the hope of self-advancement or because they firmly believe their ideas to be true.