Presentation at a Course on Principles of Epidemiology Health Research Faculty of Medicine, King Fahad Medical City October 11-12, 2017 by Professor Omar Hasan Kasule Sr. MB ChB (MUK). MPH (Harvard), DrPH (Harvard) Chairman of the Institutional Review Board / Research Ethics Committee at King Fahad Medical City, Riyadh.
LECTURE 1: THE SCIENTIFIC METHOD AND DEDUCTIVE-INDUCTIVE HYPOTHESES IN HEALTH SCIENCE RESEARCH
EMPIRICISM:
• Epidemiological methodology, following the scientific method, is empirical
• Epidemiology relies on and respects only empirical findings.
• Empiricism refers to reliance on physical proof.
INDUCTIVE VS DEDUCTIVE INFERENCE:
• Epidemiological methodology, following the scientific method, is inductive
• Inductive inference = from the specific to the general
• Induction is building a theory on several individual observations
• Deductive inference is from the general to the specific
RELATIVITY VS. ABSOLUTISM:
• Nothing is absolute, everything is relative
• Science is not deterministic or absolute
• Some sciences are deterministic than others for example laboratory data vs epidemiological data
CLASSICAL VS BAYESIAN INFERENCES:
• Classical inference depends only on the data collected at the moment. It assumes starting the experiment with a clean slate
• Bayesian inference combines prior information (objective, subjective, or a belief) with new information (from experimentation) to reach a conclusion
• Bayesian inference is a good representation of how conclusions are made from empirical observation in real life
STATISTICAL VS SUBSTANTIVE QUESTIONS AND CONCLUSIONS:
• An investigator starts with a substantive question that is formulated as a statistical question.
• Data is then collected and is analyzed to reach a statistical conclusion.
• The statistical conclusion is used with other knowledge to reach a substantive conclusion.
• Statistics has a limitations: it gives statistical and not substantive answers.
• The statistical conclusion refers to groups and not individuals.
• The statistical conclusion summarizes but does not interpret data.