The Nature of Science

What Do Scientists Assume?

Question Mark Image Credit: Microsoft Clip Art

Scientists have a certain worldview about science and their work. Their activities and practices are guided by the following assumptions:

  • The physical world is understandable.
  • Science cannot provide the answers to all questions.
  • Scientific knowledge is durable, but it does not represent absolute truth.
  • Scientific ideas are tentative (or subject to change).

What Makes Science Different From Other Ways of Knowing?

Validity - research is relevant to the question being asked Reliability - the repeatability or consistency of the research

Unlike art, philosophy, religion, and other ways of knowing, science is based on empirical research. A scientist conducts this research to answer a question that she or he has about the natural world. Empirical research relies on systematic observation and experimentation, not on opinions and feelings. These systematic observations and experiments provide research results (evidence) that must meet two criteria in order for a scientist's research to withstand thorough questioning. These two criteria are validity and reliability. Validity means that research is relevant to the question being asked. Reliability describes the repeatability or consistency of the research. Research results are considered reliable when other scientists can perform the same experiment under the same conditions and obtain the same or similar results.

Who Are Scientists and How Do They Decide What To Study?

Pediatrician vs. Surgeon
Image Credit: Microsoft Clip Art

Scientists come from all walks of life and all parts of the globe. Their diversity allows them to look at problems from a variety of perspectives and search for answers in different ways. But even though their approaches may vary, they use empirical methods of inquiry. Because science and the body of scientific knowledge is so broad, most scientists specialize — just as one doctor decides to become a brain surgeon, while another chooses to be a pediatrician. In fact, scientists often spend their entire career studying a specific topic and thus may not be qualified to evaluate the results of scientists who are working in other fields of study.

How Do Scientists Perform Scientific Inquiry?


Scientists, like detectives, work to reveal and explain the unknown, and their inquiry methods share some similarities. The table below illustrates the similarities.

Comparing the Work of Scientists and Detectives


Scientists … Detectives …
ask questions. conduct inquires.
make systematic observations. set up surveillance.
propose hypotheses. follow their intuition and instinct (based on experience) to come up with likely scenarios.
collect, analyze, and interpret data. (with help from forensic scientists) collect, analyze, and interpret evidence.
construct explanations, using appropriate evidence and reasoning to justify these explanations. infer or deduce what happened based on the evidence collected.
evaluate or critique others' explanations. investigate other leads to exclude all other possibilities and suspects.
communicate their research methods and findings to other scientists and the public. turn over their evidence and findings to prosecutors and the courts.

Jury Image Credit: Microsoft Clip Art

But this is where the similarity ends. In our legal system, a jury or judge makes a decision about which side is correct. Once the decision is made, it is usually final (apart from an appeal) because a person can be forced to stand trial only once for a particular crime. The scientific community, however, oftentimes must consider multiple hypotheses to explain the same phenomenon, and scientific inferences are always open to reevaluation by other scientists.