Research Methods Flashcards
(187 cards)
What are extrenuous variables?
The only thing that should affect the IV is the DV however in some experiments there are extrenuous variables. Any other variables that interfere should be controlled or removed, these are called extrenuous variables. There are participant variables: Age, gender, intelligence, personality etc and situational variables such as lighting, weather, time of day, noise etc
What are confounding variables?
These variables do change systematically with the IV. This could be unexpected events eg if the first 10 out of 20 participants saw something exciting before they went in and the last 10 participants did not so this event results in another IV. So when the first group are different we have to take both into account
What are demand characteristics?
Participants are not passive in experiments and will spend a large time trying to find out what the new situation they are in which means they will find clues to understand the experiment. This means that they will behave differentely to how they would normally as they are trying to please the experimenter or sabotage the experiment and their behaviour is no longer natural.
What are investigator effects?
This is where the experimenter may smile or make eye contact with some participants more than others which will make them behave differentely. We tend to give what we expect ie more energy. There can also be leading questions which lead a participant to a certain answer.
What is randomisation?
This can be used to minimise the effects of confounding and extrenuous variables. This is a chance method that can reduce the researchers unconscious bias. Examples are randomising the lists or changing the order the conditions are done in
What is standardisation?
All participants should be part of the same environment, information and experience which includes standardised instructions
What are independent groups?
This is when two seperate groups of participants experience two different conditions. They would experience one level of the IV only. There is usually and experimental condition and a control condition. The performance of the two groups would be compared
What are repeated measures?
This means that all participants would experience both conditions of the experiment ie each would experience condition A and then later would experience condition B and two mean scores would be compared
What are matched pairs?
Matched pairs are together on variables or variables relevent to the experience ie in a memory study the pairs may be matched based on IQ levels (first and second, third and fourth and so on) and then one from each pair will be allocated a condition as an attempt to control confounding variables.
Evaluate independent groups
An issue with the independent groups design is that there may be participant variables. If the experimenter finds a different in means for the groups in the DV, participant variables may have played into it. This acts as a confounding variable which reduces validity
They are less economical as each participant contributes to a single result so twice as many would be needed
Strengths: Order effects do not effect
Participants are less likely to guess the aims
Evaluate repeated measures
Issues: The order significantly effects the way that the experiment goes. This can be fixed using counterbalancing. This is where half the participants would take part in condition A and then B and the other half would do condition B first and condition A second. Order effects can also cause boredom and fatigue or they may have developed skills so they will be better or worse on the second condition depending on which confounding variable it is. It is also more likely that they will work out the aims of the study
Strengths: Participant variables are controlled so higher validity and fewer are needed
Evaluate matched pairs
Strengths: Participants only take part in one so order effects don’t exist
Issues: Participants can never be matched exactly
May be time consuming and expensive
What is a laboratory experiment?
They are conducted in highly controlled experiments (not always a lab)
Give the strengths of laboratory experiments
They have high control over confounding and extrenuous variables so change in the DV is ensured to be caused by manipulation of the IV. This results in high internal validity
Replication is possible because new variables cannot be introduced
Give the limitations of a laboratory experiment
They lack generalisability as it is an artificial setting and participants may behave in certain ways (low external validity)
They are aware they are being tested so there will be demand characteristics
It has low mundane realism
What is a field experiment
The IV is manipulated in a natural setting, researcher goes to the particpants usual setting
Give the strengths of a field experiment
They have a higher mundane realism due to the natural environment
Produce more valid and authentic behaviour (high external validity)
Give the limitations of a field experiment
There is a loss of control over CVs and EVs so cause and effect is more difficult to establish and is less precise
There are ethical issues as participants are unaware of the study and cannot consent and the rsearch is an invasion of privacy
What is a natural experiment?
The researcher measures the effect of the IV on the DV however they have no control and cannot change the IV ie before and after a natural disaster. The DV may also be naturally occurring or ay be devised by the experimenter and then measured in the field or lab
Give the strengths of a natural experiment
They provide oppurtunities for research that may not otherwise occur for practical or ethical reasons
High external validity as they study real world problems
Give the limitations of a natural experiment
May only happen very rarely so reduces oppurtunities for research, this limits generalisation
Participants may be randomly allocated to different conditions (only in independent groups design) researcher may be unsure whether or not the IV is directly affecting the DV
Such research may be conducted in a lab and therefire lacks realism and has demand characteristics
What is a Quasi experiment?
Quasi experiments have an IV that is based of existing differences between people such as age or gender so the IV is not manipulated and cannot be changed. The DV may be naturally ocurring or may be measured in a field or a lab
Give the strengths of a Quasi experiment
Often carried out under lab controlled conditions so therefore can be replicated
Give the limitations of a Quasi experiment
They occur naturally so they can’t randomly allocate participants so therefore there may be confounding variables
The IV is not manipuated so we cannot claim that it has caused any observed change