Scientific Method

The Scientific Method Prof T RangaRao MD Resource Person

Dr NTR University of Health Sciences Andhra Pradesh, India

What is Science?

The Scientific Method

What is Science ? Science refers to a system of acquiring knowledge – based on empiricism, experimentation, and methodological naturalism – aimed at finding out the truth. The basic unit of knowledge is the theory, which is a hypothesis that is predictive. The scientific method is a process for evaluating empirical knowledge under the working assumption of methodological materialism, which explains observable events in nature as a result of natural causes, rejecting supernatural notions. Science refers to any systematic field of study or the knowledge gained from it. Wikipedia

Science & Research Science is defined as:..knowledge ascertained by observation and experiment, critically tested, systemised and brought under general principles.. z Research is defined as:..systematic investigation towards increasing the sum of knowledge. z

Using the scientific method requires that one be a good observer.

observation uses the five senses

inference involves a judgment or assumption

The Skeptical Chemist Published “The Sceptical Chemist” (in 1661)

…stated that scientific speculation was worthless unless it was supported by experimental evidence. evidence Robert Boyle

This principle led to the development of the scientific method. method

Data Observations are also called data.

There are two types of data. qualitative data

quantitative data

descriptions; no numbers

measurements; must have numbers

Parts of the Scientific Method Identify an unknown. z Make a hypothesis (a testable prediction). z Experiment to test the hypothesis. z Draw a valid conclusion. z

A Scientific Experiment procedure the order of events in an experiment; the “recipe”

variable any factor that could influence the result

Experiments must be controlled; they must have two set-ups that must differ by only one variable. The conclusion must be based on the data.

A Controlled Experiment?

Scientific Method

z

Observations Hypothesis Experimentation – Controlled (one variable changed at a time) – Collect data (quantitative and qualitative) – Analyze data (graph, statistics…trends) Form valid conclusion.

z

After many experiments…form a theory.

z z z

Scientific Law vs. Scientific Theory A law states what happens. Law of Gravity A theory tries to explain why or how something happens. Theory of Gravity Atomic Theory Collision Theory of Reactions

Scientific Method

Make Makeobservation observation Ask Askquestion question Develop Develop hypothesis hypothesis

Test Testhypothesis hypothesis with withfurther further experiments experiments

Test Testhypothesis hypothesis with withan an experiment experiment

Revise Revise hypothesis hypothesis

Analyze Analyzedata data and anddraw draw conclusions conclusions Hypothesis Hypothesis IS IS supported supported

Hypothesis Hypothesis isisNOT NOT supported supported Develop Develop theory theory

Scientific Law Charl es’s Law V1 V T1 = T 2 2

Laws of nature never change.

Theories and Laws The Earth is flat… Speeding kills (Audubon, Germany); seat belts save lives… LAW: LAW 65 mph and wear seat belt No explanation of why…but the theory is if you drive at 120 mph and crash, an ambulance won’t need to be called (only next of kin).

The Original Metric Reference

1/10,000,000

= 1 meter

1/10 m

H2O

= 1 kilogram

H2O

1 kg

1/10 m 1/10 m Length

Mass

Volume

= 1 liter

Isaac Newton Probably the most significant contributions to experimental science were made by Isaac Newton. z Newton postulated a theory and then used experimentation to test it against alternatives. z In Newtons view experiments provided knowledge of the laws that governed the whole world. z

Empiricism v Rationalism Within this process was the debate between empiricists and rationalists. z Rationalists believe that all knowledge starts in the mind. z Empiricists believe that all knowledge originates from experience. z

Rationalism Descartes’ used the method of systematic doubt and concluded that the only thing he could be certain of was his own existence - I think therefore I am. z Descartes use of the principle of analytical reductionism forms the basis of the majority Western scientific thinking over the past 350 years. z

Rationalism Reductionism is characterised by the reduction of complex entities to the simpler parts of which they are composed. z However, in the twentieth century this approach was challenged by those who believe that evidence gathered from the parts cannot necessarily be combined to describe the behaviour of the whole. z

Rationalism z

These criticisms have been particularly strong amongst those who have studied the social sciences.

Empiricism John Locke concluded that there are no such things as INNATE IDEAS but that all we know comes from experience and reflection upon experience. z Such experiences cannot be isolated from their surroundings as everything is inter-related to everything else. z Holistic approach to the scientific method. z

Systems Thinking One consequence of this holistic approach has been the development of the SYSTEMS MOVEMENT and research methodologies such as ACTION RESEARCH. z It is systems thinking that many claim is challenging the accepted views of scientific revolution. z

Conclusion It is sobering to recall that probably the most significant contribution of the Twentieth century was the downfall of Newton’s model of the world and its replacement by Einstein's. z The lesson that this provides to today's researcher is that the results from scientific work are never absolute. z

Conclusion z

Hopefully in this presentation I have shown that: – there are many different approaches to obtaining knowledge; – that the knowledge gained depends upon the approaches adopted.

z

In the remainder of the Research Methods unit you will examine some of these approaches in greater detail.