Hypothesis, theory and scientific laws.


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Hypothesis, theory and scientific laws, Research, Methodology, Basic research

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Hypothesis, theory and scientific laws.

  1. 1. Contents • • • • • • • • • • Development and structure Conditions for hypothesis Source of Hypothesis Method of Hypothesis Formulation Method of Explanation The Theory and its Structure Elements of a Theory Classification of Theory Functions of Theory Scientific Laws and Principles
  2. 2. Development and structure • The word hypothesis was derived from the Greek, hypo (under) & tithenas (to place) and suggests that when the hypothesis is placed under the evidence as a foundation they lead to support one another. • It performs this function by providing a proposed explanation which will have certain consequences, then may be confirmed or refuted by testing
  3. 3. • Refers to a definite interpretation of a given set of facts, which is put forth as a tentative suggestion and remains partly or wholly unverified. • After it is once established, it ceases to be a hypothesis and becomes a theory or explanatory principle.
  4. 4. • Webster defines hypothesis as “a tentative theory of supposition provisionally adopted t explain certain facts and to guide in the investigation of others. • Synonyms : assumption, supposition.
  5. 5. Conditions for hypothesis 1. It must be so made that deduction can be made and consequently, a decision reached as to whether or not it does explain the facts considered. 2. It should provide the answer to the problem which generated the inquiry. 3. A hypothesis should provide facts which would reveal certain propositions to be true whose truths are not known at the time. 4. It must help eliminate irrelevant facts and be simple. The simplest hypothesis that will account for the facts should be chosen.
  6. 6. Source of Hypothesis • In order for a hypothesis to originate, some problem must exist to cause someone to start looking for facts connected with this problem. • These facts are then organized . • The problem cannot even be started unless we are familiar with the subject matter in which we discover the problem.
  7. 7. • A hypothesis is believed to be relevant to a problem if it expresses determinate modes of connection between a set of facts, including the fact investigated. • Sometimes scientists see a connection between data, and then formulate a hypothesis.
  8. 8. Method of Hypothesis Formulation • The method of hypothesis is restricted to the formulation of good working suggestions and good tentative principles of explanation. • Certain general requirements or rules to be followed in reaching a hypothesis are usually given by logicians.
  9. 9. 1. The hypothesis should be conceivable and not absurd. 2. The hypothesis must be of such a character that deductions can be made from it. 3. A hypothesis should not contradict any of the known and proven laws.
  10. 10. Method of Explanation • To effect a complete explanation of a phenomenon, it is necessary to carry on the investigation until the hypothesis is fully verified.
  11. 11. Collecting the data The Formulation of Hypothesis Deduction from the Hypothesis Verification of the separate deductions.
  12. 12. • Testing a hypothesis is really not a part of its development. However, a brief outline of ways of testing a hypothesis follows and may be valuable to a better understanding of its development. 1. 2. 3. 4. 5. Observation and Experimentation. Mathematical calculation. Statistical Verification. Verification by Elimination. Verification by Disjunctive Reasoning.
  13. 13. The Theory and its Structure • Henri Poincare (1854-1912), said : “Science is built with facts as a house is built with stones, but a collection of facts is no more science than a heap of stones a house.” • Samuelson develops his idea more precisely in a formal definition : a theory is .. “a set of axioms, postulates, or hypotheses that stipulate something about observable reality
  14. 14. • Poincare & Samuelson imply or recoginze that theory provides an organized substantiated plan of reasoning about phenomena and their interrelationships. • Theory provides a systematic method for conducting scientific research and cultivates the scientific mind toward fertile areas of knowledge discovery.
  15. 15. Elements of a Theory • The Structure of a theory consists of certain elements that, built one upon the other, form a deductive system of reasoning. • These elements are: 1. Assumptions 2. Theoretical terms 3. Theorems
  16. 16. Assumptions • The Assumptions of a theory form a logical skeleton for the explanatory system and define the basic notions about the system. • Such a conceptual world or abstract model is simpler than the real world and contains only the forces that the theory asserts to be important.
  17. 17. Theoretical terms • Theoretical terms signify various entities that cannot be specified except by way of some theory which postulates their existence, or certain ideal limits of a theoretically endless process. • As coordinators of the variables or entities in the theory to observable traits of things, these terms may be thought of as a set of rules that define the class of phenomena for which the model can be taken to be an adequate representation of the real world.
  18. 18. Theorems • Theorems should be logically deducible from the statements in the assumptions. • An interpretation or model for the abstract assumptions supplies some flesh for the skeletal structure in terms of more or less familiar, conceptual, or visualizable materials.
  19. 19. Classification of Theory Pure theory • Considered to be logical deduction from assumed promises. • Relying on intellectual speculations, pure theory builds a conceptual model for explaining observable phenomena. Practical theory • It eschews all reference to deductive reasoning, generalizes relations abstracted from observable phenomena . • It is thought to put meaning and purpose into the logic of pure theory for the solution of practical problems.
  20. 20. Classification of Theory …ctd • An Axiomatizable theory consist of all the logical consequences of a specified set of assumptions and can be deduced from a subset of such consequences, since all the assumptions are their own consequences and belong themselves to a theory . • Axiomatizing a theory amounts to constructing an axiomatic system whose assumptions, theoretical terms, and theorems add up to this theory.
  21. 21. • Phenomenological theories have all their statements, both the assumptions and the consequences, about observable phenomena. • Since the assumptions of these theories can be validated, such assumptions reduce to facts or laws and do not therefore, enlarge the cognitive potentialities of science.
  22. 22. • Transcedent theories, as opposed to phenomenological theories, contain fact-like or law-like consequences which cannot be validated. • If these theories are justifiable, they have to be included with in the context of a theory system and the theory thus becomes indispensable and cannot be replaced by any combination of fact-like statements.
  23. 23. • Interdependent theories : For historical reasons &/or to facilitate the division of scientific labour, ramified systems of theories are clustered in a single discipline, or a special science. • Through inference or definition, one theory may be dependent on the other or a whole heriarchy of theory may be constructed. • This interdependence is usually reciprocal.
  24. 24. • Self-correcting systems of theories are sequences of theories in which each theory presupposes, extends, and refutes its predecessor. • This steady advance toward new theories which replace their predecessors seems to constitute the fundamental pattern of scientific progress.
  25. 25. Functions of Theory • Theory has the particular functions of defining, systematizing, explaining, and predicting the relationships between phenomena.
  26. 26. Language theory • Designed to promote systematic & organized methods of reasoning. • It is a set of tautologies. A body of substantive hypotheses • Theory abstracts features of complex reality to explain, predict, and validate relationships between things.
  27. 27. Scientific Laws and Principles • A scientific law is a statement of universal relationships between classes, events, or facts. • The term scientific law is often used ambiguously, sometimes for the principle and sometimes for the formula or statement of the principle or the phenomenon. • The statement of scientific law in a simple form is an abbreviation and simplification of experience of research that establishes a scientific law.
  28. 28. • Scientific laws are generalized from facts obtained in observation, from other laws, and by logical processes. • Scientific laws are most often formulated from the facts that are observed in nature. • Scientific laws are sometimes deduced from primary laws. For instance, Kepler’s three laws are derived from the laws of gravitation and explain the orbits of the planets around the sun.
  29. 29. • Scientific laws become established when a majority of scientists in the field accept the explanation as best possible to explain result of sound empirical evidence. • Scientific laws may need correction after a time in the light of new knowledge. • The correction may be in the form of adjusting, extending, or may be completely rejected.