Scientists must observe how a phenomenon occurs and why it occurs. Scientists have to be clear about 'what to' observe and 'how to' observe it. The observations made by the scientists have to be correct and independent of their sentiments and wishes. Scientific observations may be about natural events or man made machines. All these observations are carried out systematically through carefully designed experiments or surveys in order to explain natural or social phenomena. These observations are then put in order, ie classified, carefully recorded in the form of tables or graphs and analysed. The aim is to discover regularities and patterns in the factual information obtained. A number of questions may be posed on the basis of observations.
The next step is to formulate a hypothesis. A hypothesis is a statement put forward in the basis of reasoning, about the things that are being studied. It is an attempt to answer the questions that are posed. A hypothesis is formulated by taking into account all the observations that are known about the phenomenon under investigation. It tries to explain the known or predict the unknown but possible features of the phenomenon. Hypothesis can be described as an inspired guess based on reason and experience. Both inductive and deductive logic are used to frame a hypothesis.
a) Inductive Logic
A student comes late to the class for 3 days in a row. Then the teacher thinks that he will be late for the 4th day also. This is called inductive logic.
If we have direct evidence about only a part of the phenomenon and if on that basis, we infer about the properties, behavior and other features of the whole phenomenon then we are using inductive logic. Inductive logic can be misleading and have different degrees of credibility and reliability. Conclusions have to be further tested for their reliability.
b) Deductive Logic
In a multiple choice test, if we find the answer by eliminating the other options then we are using deductive logic. For eg: For a question, there are 3 choices A,B,C. And suppose you know that B and C are not the correct answers, then A becomes the correct choice. This is deductive logic.
In deductive logic, the reasoning is more direct and we come to the answer by deducting the known quantities.
Logical analysis involves risk or doubt. To test the hypothesis, we can use experiments.
Experiments are situations designed to make certain observations under strictly controlled conditions. This sometimes involves mimicking nature. This allows the natural phenomena to be simplified for step-by-step study. The objective of an experiment may sometimes be to observe phenomena more minutely by the use of very sensitive instruments. The results of experiments will prove of disprove a particular hypothesis.
4. Laws, Models And Theories
We get scientific knowledge from observations and experiments. These results are tied up and related to each other in the form of logical, coherent theories or laws. A relationship between thing covering results of observations and experiments over a wide range of individual cases is called a law.
A model is an artificial construction to represent the properties, behavior or any other features of the real object under study. Eg: Human heart.
A theory is a set of few general statements that can correctly describe or explain all experimental observations about the properties and behavior of a large number of varied objects, phenomena, situations or systems.