7 Major Steps of Scientific Method in Biology with explanation

7 Major Steps of  Scientific Method in Biology

Definition of Scientific Method

Scientific method is an organized and systematized effort to gain knowledge that uses observation and experimentation to describe and explain nature or natural phenomenon. It includes collection of data through observation and experimentation and formulation and testing of hypothesis.

Steps involved in a scientific method or research

Watch a simple 5 minute video here

Step I: Define the problem through observation and by asking questions.

Make an observation. Based on the observation, ask questions. Why, how, what?.  Preliminary answers to these questions will help you to define the problem.  The observation should be correct and repeatable. Observation can be direct using senses or indirect with the help of instruments.

Step II: Research the problem or Review of literature

Research the problem:  This step is often called as review of literature. It is the process of collecting all available information on the selected topic from available authentic sources. It includes research journals, books, periodicals etc. Review of literature will give the researcher a clear picture about the selected topic, helps in making good hypothesis and also helps in avoiding repetition of the work.

Step III: Formulate a Hypothesis

Based on review of literature, the researcher will formulate a hypothesis. Hypothesis is an educated guess, a possible answer or a predictive statement that can be tested by scientific methods or scientifically testable or measurable. This statement is based on our previous experience on the topic or based on existing knowledge (review of literature).

Hypothesis are of two types a)Null Hypothesis and b) Alternative hypothesis

Null Hypothesis

·         The null hypothesis is a hypothesis which the researcher tries to disprove, or nullify.

·         It is denoted by H₀  

·         Accepting the null hypothesis suggest that researchers hypothesis needs revision

Alternative Hypothesis

·         The alternative hypothesis is a hypothesis which the researcher tries to prove.

·         It is denoted by H₁ 

·         Accepting the alternate hypothesis proves that the researchers reasoning is true.

Step IV: Test Hypothesis by conducting experiments.

Here we have to design the experiment and execute the project. We often call the methodology adopted for conducting the experiment as procedure. It should be properly designed to get unbiased results. We need to determine the variables in the experiment

A variable is any factor, trait, or condition that can have different values, change in variable influences the outcome of experimental research

The variable is the factor you might measure in an experiment

Three types of variables:

1. Independent variable: The variable that researcher changes or the researcher think it will affect the dependent variable

        2. Dependent variable: The variable that is affected by change  in independent variable

      3. Controlled variable: The variable that is kept constant or same throughout the experiment.

If possible, the experiment should have a control group.

See here how is controlled variable different from control group

Scientific Method Poster

Step V: Collect and record data. Data collection may be direct (using our senses) or indirect (using scientific instruments). 

Step VI: Analyze and interpret data and draw conclusions.

Analyze data using mathematical tools or statistical software like SPSS for finding out the significance of the result. At the end of the experiment, null hypothesis may be accepted or rejected. Accepting the null hypothesis suggest that researchers hypothesis needs revision

Step VII: Report results or Publish the result. This includes preparation of report, scientific paper or presentation of results or publish it in scientific journals so that your finding is open to public. A theory is a hypothesis supported by large body of observation and experimental evidences. All scientific theories are subjected to revisions or modifications.