Scientific thinking

1. Scientific thinkingScientific thinking
Prof. Vajira WeerasingheProf. Vajira Weerasinghe
Professor of PhysiologyProfessor of Physiology
Department of PhysiologyDepartment of Physiology
Faculty of Medicine Faculty of Medicine
University of Peradeniya University of Peradeniya

2. ObjectivesObjectives
nDefine “science”Define “science”
nState the main goal of scienceState the main goal of science
nDifferentiate “science” from Differentiate “science” from
“technology” “technology”
nDefine “scientific method”Define “scientific method”
nDescribe the steps in scientific Describe the steps in scientific
methodmethod

3. What is science ?What is science ?
Is derived from the Latin word scientia for knowledge Is derived from the Latin word scientia for knowledge
The state of knowingThe state of knowing
Knowledge as distinguished from ignorance or misunderstandingKnowledge as distinguished from ignorance or misunderstanding
The systematic study of the natural world The systematic study of the natural world
Systematically acquired knowledge that is verifiableSystematically acquired knowledge that is verifiable
The observation, identification, description, experimental investigation, and The observation, identification, description, experimental investigation, and
theoretical explanation of phenomena theoretical explanation of phenomena
It is a method used by humans to try to make sense of the world (and It is a method used by humans to try to make sense of the world (and
universe) in which they liveuniverse) in which they live
http://www.sciencedaily.com/

4. 

5. Main goal of scienceMain goal of science
The main goal of science is to acquire The main goal of science is to acquire
knowledge about the world knowledge about the world
To explain the natural world as we observe it as To explain the natural world as we observe it as
much as possible and to search for ways of much as possible and to search for ways of
applying such knowledge for the benefit of applying such knowledge for the benefit of
humanity humanity

7. Different branches of science Different branches of science
PURE SCIENCE PURE SCIENCE
The seeking of information for its own sakeThe seeking of information for its own sake
The pursuit of knowledge for the sake of knowledgeThe pursuit of knowledge for the sake of knowledge
APPLIED SCIENCE APPLIED SCIENCE
The seeking of information that is of immediate use The seeking of information that is of immediate use
and benefit and benefit

8. Related terms Related terms
TechnologyTechnology
originates from the Greek word tekhnologia
and the Latin word technologia which
means an approach to doing something
systematically
It is the usage and knowledge of tools,
techniques, crafts, systems or methods of
organization
PhilosophyPhilosophy
is a branch of knowledge that study
general problems pertaining to existence,
knowledge, justice, truth, beauty, law,
validity, mind and language

9. TechnologyTechnology
Compared to “science”, the term , “technology” Compared to “science”, the term , “technology”
is still new as it is only used since the 18is still new as it is only used since the 18
thth

centurycentury

13. Scientific medicine Scientific medicine
Medicine is the science and art of healing Medicine is the science and art of healing
humanshumans
Medical science or scientific basis of medicineMedical science or scientific basis of medicine
Medical technologyMedical technology

14. What is scientific method ?What is scientific method ?
Refers to a body of techniques for investigating phenomena, Refers to a body of techniques for investigating phenomena,
acquiring new knowledge, or correcting and integrating previous acquiring new knowledge, or correcting and integrating previous
knowledgeknowledge
To be termed scientific, a method of inquiry must be based on To be termed scientific, a method of inquiry must be based on
gathering gathering observableobservable, , empiricalempirical and and measurablemeasurable evidence subject to evidence subject to
specific principles of reasoningspecific principles of reasoning
A scientific method consists of the collection of data through A scientific method consists of the collection of data through
observationobservation and and experimentationexperimentation, and the formulation and testing of , and the formulation and testing of
hypotheseshypotheses
These steps must be repeatable, to predict future resultsThese steps must be repeatable, to predict future results
Scientific inquiry is generally intended to be as Scientific inquiry is generally intended to be as objectiveobjective as possible, as possible,
to reduce biased interpretations of resultsto reduce biased interpretations of results

16. Related termsRelated terms
EmpiricalEmpirical
information gained by means of observation, experience, or information gained by means of observation, experience, or
experiment experiment
In the scientific method all evidence must be empirical, or In the scientific method all evidence must be empirical, or
empirically based, that is, dependent on evidence or empirically based, that is, dependent on evidence or
consequences that are observable by the sensesconsequences that are observable by the senses
Empirical data is data that is produced by an experiment or Empirical data is data that is produced by an experiment or
observationobservation
HypothesisHypothesis
A suggested explanation for an observable phenomenon, or A suggested explanation for an observable phenomenon, or
a reasoned proposal predicting a causal correlation among a reasoned proposal predicting a causal correlation among
multiple phenomenamultiple phenomena

17. Inductive vs Deductive logic Inductive vs Deductive logic
INDUCTIVE REASONING: INDUCTIVE REASONING:
From a specific case to the general principle From a specific case to the general principle
Sparrows are birdsSparrows are birds
They have wings and can flyThey have wings and can fly
Robins, flamingos, owls, and eagles areRobins, flamingos, owls, and eagles are
birds, have wings and can fly birds, have wings and can fly
From this you might induct From this you might induct
that "ALL BIRDS CAN FLY." that "ALL BIRDS CAN FLY."
DEDUCTIVE REASONING: DEDUCTIVE REASONING:
From the general case to the specific From the general case to the specific
All birds have feathered wingsAll birds have feathered wings
We know that sparrows have feathered wingsWe know that sparrows have feathered wings
Therefore, we can deduce that "Sparrows are birds.“Therefore, we can deduce that "Sparrows are birds.“

18. Inductive vs Deductive logicInductive vs Deductive logic
The problem with this is the "inductive leap“The problem with this is the "inductive leap“
When you make the jump from many observations to When you make the jump from many observations to
saying that your observation is true in all cases, saying that your observation is true in all cases,
you are making a generalization that might not be you are making a generalization that might not be
correct every time correct every time
Although generalizations can be useful, the wise Although generalizations can be useful, the wise
scientist is always aware that there may be scientist is always aware that there may be
EXCEPTIONS to the general ruleEXCEPTIONS to the general rule
and to the possibility that the "general rule“ might and to the possibility that the "general rule“ might
eventually be found to be wrongeventually be found to be wrong

19. Inductive vs Deductive logicInductive vs Deductive logic
Let's take an example Let's take an example
You suddenly come upon an ostrichYou suddenly come upon an ostrich
It has wings, and all the other characteristics It has wings, and all the other characteristics
you'd ascribe to a bird--BUT IT CANNOT FLY!you'd ascribe to a bird--BUT IT CANNOT FLY!
Or a bat, it can fly, has wings BUT NOT A BIRDOr a bat, it can fly, has wings BUT NOT A BIRD
Does this mean that your general rule is always wrong? NoDoes this mean that your general rule is always wrong? No
But it does mean that there are exceptions, and you must be But it does mean that there are exceptions, and you must be
ready to find them!ready to find them!
The human mind is creative in its inductive reasoning, but it is The human mind is creative in its inductive reasoning, but it is
not omniscient (all-knowing) or infallible!not omniscient (all-knowing) or infallible!
This is why scientists use deductive reasoning in their scientific This is why scientists use deductive reasoning in their scientific
endeavors. Such reasoning is less susceptible to this type of errorendeavors. Such reasoning is less susceptible to this type of error

20. LogicLogic
premise, inference and conclusion premise, inference and conclusion
All insects have wings (premise)All insects have wings (premise)
Woodlice are insects (premise)Woodlice are insects (premise)
Therefore woodlice have wings (conclusion)Therefore woodlice have wings (conclusion)
All fish live in the sea (premise)All fish live in the sea (premise)
Dolphins are fish (premise)Dolphins are fish (premise)
Therefore dolphins live in the sea (conclusion)Therefore dolphins live in the sea (conclusion)

23. All basketballs are round.
The Earth is round.
Therefore, the Earth is a basketball.

24. Hypothetic-deductive methodHypothetic-deductive method
The formulation of an hypothesis (a tentative The formulation of an hypothesis (a tentative
answer to a question) and the execution of answer to a question) and the execution of
experiments from which one may deduce a experiments from which one may deduce a
general answer to the hypothesisgeneral answer to the hypothesis

25. Steps in scientific methodSteps in scientific method
1.1.Observation Observation
2.2.Asking a critical question Asking a critical question
3.3.Developing a hypothesis Developing a hypothesis
4.4.Making a prediction that can be tested Making a prediction that can be tested
5.5.Performing experiments to test the prediction Performing experiments to test the prediction
6.6.Collecting and analyzing data Collecting and analyzing data
7.7.Making a logical conclusion based on Making a logical conclusion based on
experimental resultsexperimental results

27. Scientific methodScientific method
Observing and stating a research problemObserving and stating a research problem
Forming a hypothesis: gather information about Forming a hypothesis: gather information about
the observed phenomenon and make a the observed phenomenon and make a
hypothesishypothesis
Testing the hypothesisTesting the hypothesis
Experimentation Experimentation
VariableVariable
OutcomeOutcome
Control experimentControl experiment
Recording and analysing resultsRecording and analysing results
Forming a conclusion Forming a conclusion

29. http://www.nobelprize.org/
http://www.nobelprize.org/nobel_prizes/medicine/laureates/1905/
http://www.nobelprize.org/nobel_prizes/medicine/laureates/1906/
http://www.nobelprize.org/nobel_prizes/medicine/laureates/1923/
http://www.nobelprize.org/nobel_prizes/medicine/laureates/1930/

32. No amount of experimentation can
ever prove me right; a single
experiment can prove me wrong.
Albert Einstein