Falsifiability - the scientific method requires a hypothesis which can be tested and is falsifiable. Once the findings of a study have been analysed, we must reject either the hypothesis or the null hypothesis.
Advantage because - unfalsifiable theories lack validity. (N.B. Although it is not possible to prove that a hypothesis is correct, it is possible to prove that it is false.)
- Freud claimed that all men have repressed homosexual tendencies.
- If a man seems to have no repressed homosexual tendencies, it can be argued that they are present, but too repressed to be noticeable.
- In this way, Freud's theories are unfalsifiable, therefore untestable, and lack support for this reason.
Objectivity - Objectivity involves operationalising terms and making sure that all of the variables are measurable, in order to ensure that the findings can't be interpreted to fit in with different people's opinions, beliefs or values (i.e. subjectively).
Advantage because - if variables aren't measured objectively, the findings can be interpreted by the researcher (researcher bias) and the validity of the findings is uncertain.
- Gardner and Gardner (Teaching Sign Language to a Chimpanzee) used a strict set of criteria to judge whether Washoe had learnt a sign.
- Due to these criteria, everyone agreed that she had made a sign and it was impossible for a gesture to be wrongly (and subjectively) interpreted as a sign.
Replicability - scientists record and standardise their methods so that the same procedures can be replicated.
Advantage because - by replicating a study we can establish whether similar results are obtained again, and if the results are similar it shows the findings to be reliable.
- Milgram's study into obedience has been replicated across different cultures and genders with similar findings.
- This makes it possible to generalise the findings to the wider population and shows good reliability.
Control - control of extraneous variables is central to the laboratory experiment. The lab experiment is often used in the scientific method, as it enables a cause and effect relationship to be established.
Advantage because - the experimenter can be sure that only manipulation of the independent variable (IV) caused the change to the dependent variable (DV). So, a causal relationship can be established.
- Twin studies compare identical twins to control for genetics.
- This means that the researcher can be sure that any difference between them is not due to genetics.
Empiricism - An empirical approach produces data by experimentation and observation, producing testable hypotheses.
Advantage because - this provides evidence regarding theories, so we can know the truth about a theory without requiring faith or belief.
- Hundreds of pilgrims visit Lordes in France every year, believing that it will cure them. They do not need evidence to do this, only faith.
- In contrast, Viguera et al found that over 60% of manic depression patients improved when treated with lithium. No faith is required to believe this, as there is evidence supporting it.