Scientific thinking
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Scientific thinking






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    Scientific thinking Scientific thinking Presentation Transcript

    • Scientific thinking Prof. Vajira Weerasinghe Professor of Physiology Department of Physiology Faculty of Medicine University of Peradeniya
    • Objectives
      • Define “science”
      • State the main goal of science
      • Differentiate “science” from “technology”
      • Define “scientific method”
      • Describe the steps in scientific method
    • What is science ?
      • Is derived from the Latin word scientia for knowledge
      • The state of knowing
      • Knowledge as distinguished from ignorance or misunderstanding
      • The systematic study of the natural world
      • Systematically acquired knowledge that is verifiable
      • The observation, identification, description, experimental investigation, and theoretical explanation of phenomena
      • It is a method used by humans to try to make sense of the world (and universe) in which they live
    • Main goal of science
      • The main goal of science is to acquire knowledge about the world
      • To explain the natural world as we observe it as much as possible and to search for ways of applying such knowledge for the benefit of humanity
    • Different branches of science
        • The seeking of information for its own sake
        • The pursuit of knowledge for the sake of knowledge
        • The seeking of information that is of immediate use and benefit
    • Related terms
      • Technology
        • 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
      • Philosophy
        • is a branch of knowledge that study general problems pertaining to existence, knowledge, justice, truth, beauty, law, validity, mind and language
    • Technology
      • Compared to “science”, the term , “technology” is still new as it is only used since the 18 th century
    • Scientific medicine
      • Medicine is the science and art of healing humans
      • Medical science or scientific basis of medicine
      • Medical technology
    • What is scientific method ?
      • Refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge
      • To be termed scientific, a method of inquiry must be based on gathering observable , empirical and measurable evidence subject to specific principles of reasoning
      • A scientific method consists of the collection of data through observation and experimentation , and the formulation and testing of hypotheses
      • These steps must be repeatable, to predict future results
      • Scientific inquiry is generally intended to be as objective as possible, to reduce biased interpretations of results
    • Related terms
      • Empirical
        • information gained by means of observation, experience, or experiment
        • In the scientific method all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses
        • Empirical data is data that is produced by an experiment or observation
      • Hypothesis
        • A suggested explanation for an observable phenomenon, or a reasoned proposal predicting a causal correlation among multiple phenomena
    • Inductive vs Deductive logic
      • INDUCTIVE REASONING: From a specific case to the general principle
        • Sparrows are birds
        • They have wings and can fly
        • Robins, flamingos, owls, and eagles are birds, have wings and can fly
        • From this you might induct that "ALL BIRDS CAN FLY."
      • DEDUCTIVE REASONING: From the general case to the specific
        • All birds have feathered wings
        • We know that sparrows have feathered wings
        • Therefore, we can deduce that "Sparrows are birds.“
    • Inductive vs Deductive logic
      • The problem with this is the "inductive leap“
      • When you make the jump from many observations to saying that your observation is true in all cases, you are making a generalization that might not be correct every time
      • Although generalizations can be useful, the wise scientist is always aware that there may be EXCEPTIONS to the general rule
      • and to the possibility that the "general rule“ might eventually be found to be wrong
    • Inductive vs Deductive logic
      • Let's take an example
      • You suddenly come upon an ostrich It has wings, and all the other characteristics you'd ascribe to a bird--BUT IT CANNOT FLY!
      • Or a bat, it can fly, has wings BUT NOT A BIRD
      • Does this mean that your general rule is always wrong? No
      • But it does mean that there are exceptions, and you must be ready to find them!
      • The human mind is creative in its inductive reasoning, but it is not omniscient (all-knowing) or infallible!
      • This is why scientists use deductive reasoning in their scientific endeavors. Such reasoning is less susceptible to this type of error
    • Logic premise, inference and conclusion
      • All insects have wings (premise) Woodlice are insects (premise) Therefore woodlice have wings (conclusion)
      • All fish live in the sea (premise) Dolphins are fish (premise) Therefore dolphins live in the sea (conclusion)
    • All basketballs are round. The Earth is round. Therefore, the Earth is a basketball.
    • Hypothetic-deductive method
      • The formulation of an hypothesis (a tentative answer to a question) and the execution of experiments from which one may deduce a general answer to the hypothesis
    • Steps in scientific method
      • Observation
      • Asking a critical question
      • Developing a hypothesis
      • Making a prediction that can be tested
      • Performing experiments to test the prediction
      • Collecting and analyzing data
      • Making a logical conclusion based on experimental results
    • Scientific method
      • Observing and stating a research problem
      • Forming a hypothesis: gather information about the observed phenomenon and make a hypothesis
      • Testing the hypothesis
      • Experimentation
        • Variable
        • Outcome
        • Control experiment
        • Recording and analysing results
        • Forming a conclusion
    • No amount of experimentation can ever prove me right; a single experiment can prove me wrong. Albert Einstein