The use of the scientific method in Psychology

1. The use of the scientific method in Psychology A2 Psychology

2. Introduction • Psychologists, like all scientists, use the Scientific Method to produce valid explanations of the world around them. • This method has both advantages and disadvantages.

3. The Scientific Method • The Scientific process starts with observations of phenomena in the world. • In the Inductive Model this then leads to the developments of hypotheses. • Hypotheses are tested which may lead to new questions and new hypotheses. • Eventually such data may be used to construct a theory. • The Deductive Model theory construction at the beginning of the process, after making observations.

4. Example: the spontaneous generation theory Scientific method Life emerges from non-living matter Make Observations Theory Inductive process Mice emerge from dirty socks Reject the theory No mice!!!! Deductive process Hypothesis Place dirty socks in a glass jar for a few days Experiment

5. Scientific Method • Referring back to the definition of ‘Scientific’, any research can be considered scientific as long as it collects data in an objective, controlled manner. • The following research methods have been put in order of how scientific they are considered to be. • Lab Experiments • Field Experiments • Natural Experiments • Interviews/Questionnaires • Observations

6. Advantages – The Scientific Method is Empirical • The left picture is a burger from McDonalds. • Or it is at least what you are led to expect you will get. • What about reality? • You may think you know something but unless you test this empirically you cannot know if it is true. • The right picture is the empirical evidence of what the burgers are really like.

7. Advantages – The Scientific Method is Empirical • So what is Empirical Data? • Empirical data is information gained through direct observation or experiment rather than reasoned argument or unfounded beliefs. • The Scientific aims to collect the facts. • Why is this an advantage? • People can make claims about the truth of a theory or the benefits of a treatment but the only way we know such things are true is through empirical evidence.

8. Advantages – The Scientific Method is Objective • An important aspect of empirical data is that they are objective. • What does this mean? • That the data is not affected by the expectations of the researcher. • Systematic collection of measurable data is at the heart of the method.

9. Advantages – The Scientific Method is Objective • How would an experimenter allow for greater objectivity? • Usually via standardised procedures and instructions. • Why is this an advantage? • Without objectivity we have no way of being certain that data collected is valid.

10. Advantages – The Scientific Method is Falsifiable • The aim of the Scientific Method is to test hypotheses by falsifying them. • i.e. rejecting a null hypothesis. • Why is this an advantage? • Because it is not possible to prove a hypothesis correct but you can prove it is wrong. • i.e. falsify it. • “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”

11. Advantages – The Scientific Method is controlled. • The ideal form of the scientific method is a lab experiment because is enables the researcher causal relationships. • What is a causal relationship? • Showing cause and effect. • The experimental method is the only way to do this – • where we vary one factor (independent variable) and observe it’s effects on the a dependent variable.

12. Advantages – The Scientific Method is controlled. • In order for this to be a ‘fair test’ all other conditions must be controlled, and the best place for this is in a lab setting. • What are extraneous variables? • Any other variables apart from the IV that could in truth affect the DV. • Why is this an advantage? • If we can’t demonstrate causal relationships then we can’t be sure, for example, a person’s anxiety was reduced by the drug used.

13. Advantages – The Scientific Method permits replication. • Scientists record their methods and standardise them carefully so that the same procedures can be followed in the future. • i.e. replicated. • Why is this an advantage? • Repeating a study is the most important way to demonstrate the reliability and validity of an observation or experiment. • If the outcome is the same this affirms the truth of the original results.

14. Over To You • In pairs • You need to come up with as many advantages for each study you can think of and relate the back to the advantages of the Scientific Approach. • Milgram’s (1963) study on Obedience. • Asch’s (1951) study on Conformity. • Selye’s (1935) study on Stress • Loftus and Palmer’s (1974) study on Eyewitness Testimony. • Gibson and Walk’s (1960) study of Depth Perception.

15. Other Advantages • Cause and Effect • The Scientific Method lets us state that it is the IV causing changes in the DV. • Quantitative Data • This can be collected and then be analysed using descriptive and inferential statistics tests, which can then be used to prove or disprove a hypothesis. • Participants • With Scientific methods, especially lab experiments, you can choose the participants that best represent your target population.

16. Disadvantages –The scientific method may lack internal validity • Problems include:- • Situational variables • Participant variables • Demand characteristics • Why is this a disadvantage? • The observed effects may be due to variables other than the IV.

17. Disdvantages – The scientific method may lack external validity • Ecological validity is a problem when artificial settings are used. • Why is this a disadvantage? • Findings cannot be generalised to the real world phenomena

18. Disadvantage – The scientific method can be reductionist • Operationalised variables in experiments and behavioural categories in observations reduce the complexity of behaviour. • Why is this a disadvantage? • Explanations of behaviour become over-simplified.

19. Disadvantages – The scientific method may ignore individual differences • The nomothetic approaches looks to generalise findings to all people. • Why is this a disadvantage? • Uniqueness and difference between genders, cultures and ages are ignored.

20. Disadvantages – The scientific method raises ethical issues • Experimental and observation methods often involve psychological harm and deception which is seen as necessary to maintain scientific rigour. • Why is this a disadvantage? • Participants may be harmed • Psychology could be brought into disrepute.

21. Other disadvantages • Investigator affects • The scientific method does not acknowledge that subjectivity of the researcher can affect the results. • Cultural/gender biases • A necessity to be able to generalise scientific findings means that they could be ethnocentric/androcentric.

22. Example essays • Read through the example essays and highlight and identify the key advantages/disadvantages. • Highlight in a different colour where the person has used examples of research to support their arguments • Highlight in a different colour linking/signpost words used to give the essay good structure.

23. Examples essays • Identify three things that you have learnt/found useful from reading these essays

24. Collaborative essays • You are going to complete an essay each by building on the points already made by others. This is how:- • Everyone write an introduction to the question:- • Discuss the advantages of using the scientific method in psychology (15) • Write one point including one advantage, reason why it’s good and an example -pass your essay on. • Read the comments already written and write the next point then pass it on. • Do this until we have 5 points. • Return the essays to the original writer and mark them using the handout with the bubbles.