- Independant Variable (IV) - Part of the study which can be manipulated. For example, a study on how effectively students could do their homework in front of a television. The IV would be the television as it could be manipulated (turned off or removed).
- Dependant Variable (DV) - This is what we would expect to change when we manipulate the IV.
- Extraneous Variables (EV) - This could be a number of things, for example, one group of participants having a better memory than the other, or even the alertness different people have at different times of day. If an experimenter fails to control the EV's then the results of the experiment are meaningless. Although the IV is meant to change the DV, The EV can have an affect on the DV also. The researcher must ensure that EV's are controlled.
- Control is vital in all experiments, without it the results are useless as the experimenter may have unintentionally tested what they intended to test.
A Psychological study must have realism, without it, the study would lack mundane realism making it useless. Studies cannot be too artificial!
Mundane Realism - This is how the experiment mirrors the real world. For example, in the study by Loftus and Palmer, it can be argued that the study lacks mundane realism as watching a car crash on a tape is not the same as witnessing it in real life.
- However it can be argued that some artificial experiments are needed. Coolican (2004) Claims that Lab experiments are artificial in order to eliminate extraneous variables that are present in the real world, they are intended to test a theory.
- He claims that in order to apply these results to real life, the theory can be re-tested in less artificial settings.
- He also argued that some artificial experiments can be applied to real life, i.e if a thief comes into a lab and robs someones bag, how can this not be like a real life robbery?
- Just because a study is conducted in a natural setting, it doesn't mean that it can be generalised. There are many other factors which need to be controlled in order for a study to have generalisability.
- For example, if a study is conducted using only American Under-graduates, it would be difficult to apply to other ages and also other cultures.
- For every age group and culture results could be different. It becomes difficult to determine whether or not the theory can be applied elsewhere.
- It is important that a study can be applied to the real world!
Internal & External Reliability! :D
Internal Validity - What goes on inside a study!
- Did the manipulation of the IV cause the change in the DV?
- Did the researcher test what they intended to test?
- Whether the study had or lacked mundane realism.
- High internal validity is needed in order for a study to be accurate. Extraneous variables must be controlled.
External Validity - Affected by Internal Validity! How generalisable is the study?
- Internal Validity must be present for their to be ANY external validity.
- Can the study be generalised to other places or settings? This is known as Ecological Validity.
- Can it be generalised to different people or populations? This is known as population validity.
- Can it be generalised to different times? This is known as Historical Validity.
Informed Consent - Informing the Participant what they will be required to do and informing them of the aim of the study. However this is not always possible as telling a participant the aim of a study may influence their behaviour affecting the results of the study. Researchers MUST gain informed consent in order to conduct their study
Deception - Sometimes it is necessary to deceive participants as if they know too much about the study they may act in a way in which they think will help the experimenter, rendering the study useless. This means that participants cannot always give complete informed consent. It is only acceptable to hold back some necesarry information, not too much as that would be unethical.
The right to Withdraw - If a participant feels uncomfortable or wishes to no longer take part in the study, they have the right to withdraw. It is also important that the participant is aware that they can do so. This can be compromised by payment to participants. Some may not feel as if they can withdraw as they are being paid to participate.
Protection from psychological and physical harm - Researchers must ensure that the questions being asked or what they are being asked to do in a study will not harm the participants nor cause them any distress.
Ethical Issues Continued!
Confidentiality - Experimenters need to publish the results of the study, however, they can promise anonymity. This means that no participants names will be found mentioned in the results. By experimenters promising this it ensures that all participants have confidentiality.
Privacy - Very difficult for experimenters to avoid an invasion of privacy. Experiments should only take place in appropriate settings (i.e. parks) Not in inappropriate settings (i.e. someones home).
- THESE TWO MUST NEVER BE CONFUSED WITH ONE AND OTHER. Confidentiality is the reassurance that no personal information will be passed on, Privacy is the avoidance of invading a personal space of a participant!
Dealing with Ethical Issues!
Ethical Guidelines - The British Psychological Society (BPS) reguarly update their ethical guidelines, they use the 'Code of Ethical Conduct'. This helps psychologists to determine what is an acceptable way to deal with ethical issues.
- There's also an APA (American) guideline for other cultures.
Ethics Committees - A study must be approved before it can be carried out. A cost-benefit analysis is carried out and the study is checked to see if there are any ethical issues with the study.
Ethical Issues and How to deal with them!
Informed Consent - Participants are asked to formally indicate their agreement to participate in the study. They must have enough information about the study in order to give 'informed' consent.
- Too much information given to the participant about the study can invalidate it.
- Participants may not completely understand what they are consenting too.
- The study may be different to what they imagined it would be
Deception - Costs and benefits must be weighed up and an ethics committee must agree that it is needed. Participants also need to be fully de-briefed following the study and offered the opportunity to withhold their data.
- Costs are not always apparent until after the study.
- Participants may feel harmed or embarrassed following the study, the de-brief cannot change this.
Ethical Issues and How to deal with them!
The right to withdraw - Participants must be informed at the beginning of a study that they have the right to withdraw themselves.
- Participants may feel as if they cannot withdraw the study as they feel it may ruin the study.
- If Participants are paid or rewarded, they may feel as if they have to continue with the study.
Protection from harm - Study must be stopped if there are any risks.
- Difficult for researchers to accurately predict the risks of the study.
Confidentiality - False names or numbers should be used for participants.
- Geographical evidence may give away the participant - this cannot always be avoided.
Ethical Issues and how to deal with them!
Privacy - People must be observed following their consent (Unless in a public place). Participants may be asked to withhold their data or give their retrospective consent.
- No universal agreement to what a public place can be classed as.
- Not everyone will find this acceptable (i.e. people in the park)
Experiments and Hypothesis!
Hypothesis - Stating what you believe to be true, the experiment will be based around proving this hypothesis.
Directional Hypothesis - Stating the direction of your results
Non-Directional Hypothesis - Stating there will be a difference between two conditions/two groups of participants.
Operationalisation & ting.
A hypothesis must be written in a testable form. The IV and DV need to be operationalised, this is when we give an idea of how each variable will be measured. It helps us too see how you're going to define and measure variables. Following this the hypothesis will be operationalised.