Scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge.
The scientific method includes four main steps:
- Observation and questioning
- Formulation of a hypothesis (potential answer to the question)
- Prediction (if the hypothesis is true, then ...), development of a proper methodology for testing hypothesis
- Testing of a hypothesis. If the hypothesis is incorrect, move to Step 2
The scientific method is the most reliable technique for obtaining new knowledge because it is purely based on measurable evidence.
Scientific articles based on scientific method are, as a rule, most clear because they are focused on verification of one or several hypotheses. The scientific method helps to prepare and run well-structured and clear experiments. Best scientific journals often require all submitted articles to be written using the scientific method.
- You observe that the yield of a chemical reaction is low (e.g., 30%) and insufficient for your purpose. Your question is - how can I increase the yield of reaction to 95%?
- You analyzed available publications, theory and your experience and formulated the following hypothesis - an increase of the reaction temperature from 25 to 70 oC will provide a yield of reaction 95%
- If the hypothesis is correct, the increase of temperature will lead to an increase of reaction yield. You develop the experimental procedure to run the reaction at different temperatures (25, 50, 70 and 90 oC) and check the yield. Other experimental parameters (concentrations of reagents, time of reaction, pressure, volumes, light, stirring, etc.) must be kept constant. To obtain reliable and reproducible data, you need to run the reaction at each temperature at least three times.
- You run the experiment, calculate the yield of reaction at every studied temperature and build a plot "yield = f (reaction temperature)". Then you decide if your hypothesis is true. If possible, you may correct the hypothesis and make a different conclusion (for example the highest yield was achieved at 90 oC)
To make it more clear, this sample experiment contained three variables:
independent - reaction temperature;
dependent - yield of the reaction
controlled - concentrations of reagents, time of reaction, pressure, volumes, light, stirring and any other parameters, which may affect the yield of the reaction.
Interactive lecture "Introduction to Scientific Method" developed by "Ecology of Biosphere" laboratory of al-Farabi Kazakh National University.