Yr 1 research methods - Types of experiment, sampling, ethical issues and ways of dealing with them. Flashcards
To review research methods from year 1
Laboratory experiment
An experiment that takes place in a controlled setting where the experimenter manipulates the IV, measures the DV and tries to control extraneous variables.
Field experiment
An experiment that takes place in a natural setting where the experimenter manipulates the IV, measures the DV and tries to control extraneous variables.
Natural experiment
Experiment in which the experimenter hasn’t changed the IV but this has already occurred naturally. The experimenter measures the effect on the DV
Quasi experiment
Experiment in which the IV is based on a difference between groups that already simply exists. The experimenter just measures the effect of this on the DV. For example, whether having a phobia or not having a phobia affects anxiety levels.
2 strengths of laboratory experiments
- More extraneous variables can be controlled
2. Replication is more possible
2 weaknesses of laboratory experiments
- They can lack external validity as they may not reflect real life behaviours (lack generalisability)
- Demand characteristics can affect behaviour as participants may pick up clues about what the experiment is testing
2 strengths of field experiments
- Higher mundane realism because the setting is natural
2. Tend to produce more authentic behaviour, especially because sometimes particpants don’t know they’re being studied.
2 weaknesses of field experiments
- Less control is possible over extraneous variables so cause and effect more difficult to establish
- Ethical issues can be more of an issue as if they don’t know they’re being studied, consent can’t be gained
2 strengths of natural experiments
- Allows study of behaviours and issues that couldn’t normally be studied for ethical or practical reasons (e.g. institutionalisation in attachment)
- Often have high external validity because they’re naturally occurring changes
2 weaknesses of natural experiments
- Happen very rarely so reduce the opportunities for research
- Participants can’t be randomly allocated to conditions in independent groups designs so affects confidence in the IV causing changes in the DV.
2 strengths of quasi experiments
- Often carried out under controlled conditions so extraneous variables can be minimised
- Replication is possible to a certain extent
2 weaknesses of quasi experiments
- Participant variables are more difficult to control
2. Participants can not be randomly allocated to conditions so confounding variables may affect the DV
Target population
The group of people that the researchers are interested in finding out about. They are a subset of the general population
Sample
The group of participants that take part in a study. This is a smaller group of the target population as you can’t normally include them all!
Representative
Used to describe how a sample used is as similar as possible to the target population
Generalisation
The extent to which the results gained can be applied more broadly to the target or general population
Sampling technique
The method used by psychologists to get their sample of participants. There are 5 you need to know.
Random sampling
All members of the target population have an equal chance of being selected
Systematic sampling
Where every ‘nth’ member of the target population is selected until you have the number required for your sample
Stratified sampling
The composition of the sample reflects the proportions of people as they exist in the target population. e.g. % of males, ages, ethnicity.
Opportunity sampling
Where the researchers simply ask a group of people who are willing and available to take part in the study
Volunteer sampling
Where a group of participants select themselves to take part in the study by volunteering to take part. e.g. respond to an advertisement
Strengths of random sample
- This reduces researcher bias
2. More likely to result in a more representative sample
Weaknesses of random sample
- You still may, randomly, end up with an unrepresentative sample
- Difficult and more time consuming to conduct
Strengths of opportunity sample
- Easy and quick to do
2. Less costly for the researcher as their time costs money
Weaknesses of opportunity sample
- Not representative of the target population as they are often drawn from the same area/street/university
- Open to researcher bias as the researcher has complete control over who they select
Strengths of systematic sample
- Avoids researcher bias as the researcher is not selecting the participants as such
- It is more likely to be representative of the target population than an opportunity sample for example.
Weaknesses of systematic sample
- More time consuming to do than opportunity or volunteer sampling
- Still potentially could lead to a biased sample, e.g. all 3rd people could actually be male?
Strengths of stratified sample
- Avoids researcher bias because once the people have been divided into their strata, the sample from each is chosen randomly
- More representative as it reflects the composition of the target population
Weaknesses of stratified sample
- More time consuming and difficult to do
2. Can never be fully representative as full stratification is never possible
Strengths of volunteer sample
- Very easy to do
2. Avoids researcher bias as participants select themselves
Weaknesses of volunteer sample
- Not representative of the target population as volunteers often have specific characteristics in their personality
- Difficult to generalise the results reliably to other people in the target or general population
Informed consent
Participants are told what the aim of the research in and what will they will be asked to do in the study, what their rights are and what their data will be used for . Participants then make a judgement about whether they want to be involved or not. It is not always used because of the problems it can create.
Deception
Deliberately misleading or withholding information from participants
Protection from harm
Participants should be protected from physical and psychological harm. This can include stress, embarrassment or undue pressure. They should not be at any greater risk than they would be in their daily lives
Privacy and confidentiality
Participants have the right to control information about themselves and their data should be protected
Ethical guidelines
This is a code of ethics produced by the BPS and researchers have a professional duty to observe these guidelines when conducting studies
Parental consent
If participants are under 16 years old, parental consent must be gained for them to be involved in research
Presumptive consent
A similar group of people are asked if they would give consent to the study in question. If they say yes, it is presumed that the sample in the actual study would also consent
Prior general consent
Participants give consent to be involved in a number of studies, in which at least one of them will involve some deception.
Retrospective consent
Participants are asked for their consent during debriefing, after they have taken part in the study. They then have the option to withdraw their data. They may not even know they have taken part in a study, or they may know and some deception may have been used
Debrief
Participants are thanked and told about the full aims of the research after the study has finished. They are told all the details about the study including other experimental conditions.
Anonymity
To protect confidentiality, participants names are not used in the write-up and their names are allocated a number or initials during the study
Cost-benefit analysis in ethics
An ethics committee will weigh up the potential benefits of the research against the costs to the participants and society before allowing research to be conducted
Briefing
Before participants take part in a study, they are introduced to it, and will give informed consent at this point, if this is being used.
