Features of science

• Why do psychologists generally use a significance level of 5%?
• The scientific process


  1. Test hypothesis

  2. Develop theory

  3. Analyse results

  4. Observations

  5. Modify and repeat

  6. Develop hypothesis
• Theory construction and hypothesis testing

  • A theory is an explanation for a phenomenon. It may be based on observations about the world or on empirical data derived from hypothesis testing
  • A hypothesis is a testable statement that makes a specific prediction
  • Theories are developed and modified through hypothesis testing
• Objectivity and the empirical method

  • Empirical evidence – data gained from the real world through (objective) observation, experimentation and measurement – not armchair theorising
  • Objectivity - events and findings are not influenced by the person conducting the research
  • A high level of objectivity increases other people's confidence in the results as they are able to say that the results would be the same regardless of who had carried out the investigation
  • The results can be used to construct theories
• Replicability


  • The ability to check and verify the results of a study by repeating the method of a study to assess if similar findings are achieved
  • The likelihood of the same results occurring twice (or more), by chance alone are much smaller than when they occur the first time
  • Findings are more likely to be reliable if they occur when the study is repeated – replication therefore increases reliability
  • If an investigation is repeated and the same results found, increases confidence in theory building
  • If results are not repeated – suggests there is a problem with the method, so the research study cannot be used to build theories
• Falsifiability


  • Karl Popper (1902-1994) argued it was not possible to confirm/prove a theory, it is only possible to disconfirm/disprove it
  • Popper concluded that no amount of evidence can prove a theory to be right, as it just takes one piece of evidence to prove a theory wrong
  • Scientists should attempt to show that their theory is incorrect – they do this by testing the null hypothesis
  • You can only say that evidence SUPPORTS a theory
• Paradigms and paradigm shifts


  • A paradigm is a theory that is accepted by the majority of scientists in a field
  • Paradigms change over time as more evidence accumulates
  • Thomas Kuhn (1962) suggested that science proceeds through revolutions
  • Three phases in science: Pre science, Normal science, Revolutionary science
• When was the behaviourism paradigm?

  1920s
• When was the paradigm shift to the cognitive revolution?

  1970s