A2 Psychology: Unit 4: Part C Part I: The application of Scientific method in psychology

The major features of science Empiricism: information gained through direct observation or experiment. Objectivity: Observations and experiments should be unaffected by bias (such as researcher expectations). Replicability: It is important that research can be repeated and similar results obtained, this adds to the reliability of the study.

Theory construction (1) Induction: involves reasoning from the particular to the general. For example a scientist may observe instances of a natural phenomenon and come up with a general law or theory. Before the twentieth century, science largely used the principles of induction- making discoveries about the world through accurate observations, and formulating theories based on the regularities observed. Newton’s Laws are an example of this. He observed the behaviour of physical objects and produced laws that made sense of what he observed.

Theory construction (2) Deduction: involves reasoning from the general to the particular, starting with a theory and looking for instances that confirm this. Darwin’s theory of evolution is an example of this. He formulated a theory and set out to test its propositions by observing animals in nature. He specifically sought to collect data to prove his theory. The hypothetico-deductive model was proposed by Karl Popper (1935), suggesting that theories/laws about the world should come first and these should be used to generate expectations/hypotheses which can be falsified. Falsification is the only way to be certain – as Popper pointed out: ‘No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion’

The scientific process Induction Deduction Observations Observations Propose theory Testable hypothesis Testable hypothesis Conduct a study to test the hypothesis Conduct a study to test the hypothesis Draw conclusions Propose theory Draw conclusions

Can psychology claim to be a science? Scientific research is desirable Psychology shares the goals of all sciences, but does using the scientific method turn psychology into a science? Miller claims it is ‘dressing up’ – pseudoscience Kuhn claims it cannot be a science as it has no single paradigm unlike other sciences. A paradigm is a set of shared assumptions, in psychology there are a number of different paradigms or approaches to explaining behaviour. Can behaviour be measured objectively? Both experimenter bias and demand characteristics compromise validity. But Heisenberg found that you cannot even measure a subatomic particle without altering its behaviour (uncertainty principle).

On the down side .. Do we really want to be a science? The scientific approach is reductionist, simplifying complex phenomena and theories down to basics. Science is also determinist in its search for causal relationships, i.e. if X determines Y. Science also takes the nomothetic approach looking to make generalisations about people and find similarities. Some psychologists argue the idiographic (individual)approach is more suitable when treating patients. Currently psychology has only moderate success when treating mental illness. Qualitative research is seen as less than scientific but triangulation can make this method more objective.

Validating new knowledge using peer review Peer review is the assessment of research by others who are experts in the same field (peers). This is usually done before research is published. This is an essential check to prevent incorrect or faulty data from entering the public domain. It is also necessary where any application for funding is concerned so it affects not just the researcher but also the university department that employs them. Every researcher should be prepared for their work to be scrutinised. Peer review is a way of establishing the validity of scientific research.

Questions that could come up Choose 2 of the following questions and answer them. 1. Briefly discuss the application of the scientific method to psychology. 2. Outline the scientific process (either induction or deduction). 3. Select one psychological theory and consider whether it is an example of induction or deduction. 4. Explain why peer review is essential to the process of producing valid scientific data.