Part 1 Flashcards
(32 cards)
What are the strengths of lab experiments?
High control over variables-In a lab experiment the vast majority of the extraneous variables can be controlled.These include participant variables or situational variables.This reduces them from becoming confounding variables(could affect the DV and make the results invalid)So lab experiments are able to establish conclusions about cause and effect.
Easy to replicate-they have high levels of control and standardization. This makes it possible for the researcher to carry out the same procedures for each participant and for other researchers to replicate the experiment .Useful as discovers results of reliability.
What are limitations of lab experiments?
Issue of low Ecological validity -as lab experiments take place in an artificial environment,usually using artificial tasks/stimuli, it means participants may not act or respond in the same way they would in a real life ‘stimuli’.Therefore,it is difficult to generalize the results (beyond the control of the lab)to explain real/everyday behavior
Problem of Demand characteristics-participants are very aware that their behavior is being recorded , and so participants might try to guess the aim of the research and produce behaviors/responses which they think the research is looking for,rather than acting in a natural way.Therefore may lack validity and so may offer very little understanding about how people really behave.
Issue of experimenter effects-possible that the investigator/experimenter subconsciously or consciously gives out clues about the true aim of the research which the participants might pick up on.This could be in the way they communicate with the participants.Furthermore they might be biased in their recording of data ,especially if they have an expectation about the results.Therefore, the very presence of the experimenter may reduce the validity of the results obtained in a lab experiment.
What are the characteristics of LAB experiments?
-The IV has been deliberately manipulated by the experimenter (to create the conditions of the experiment)
-They take place in an artificial environment ,often using artificial stimuli
-The experimenter is able to have high levels of control over an extraneous variables which could potentially affect the results,meaning it is possible to see whether our manipulation of the IV is CAUSING THE EFFECT seen on the dependent variable. Therefore, we can draw a conclusions about cause and effect from lab experiments.
What are some examples of Laboratory experiments?
Aschs research into variables affecting conformity (social psychology)
-Peterson and Peterson’s research into duration of STM (memory)
What are the characteristics of field experiments?
-The IV has been deliberately manipulated by the experimenter (to create the conditions of the experiment)
-They typically take place in the ‘usual (natural) environment of the participants as they try to increase the realism of the research
-There is more control over extraneous variables (although less than in a laboratory experiment because it takes place in a more natural experiment.)
What are some examples of field experiments?
-Bickmans’s research investigating the power of uniforms
-Lorenz’s study into imprinting in non-human animals(Developmental psychology)
What are the strengths of field experiments?
Improved Ecological Validity-This is because a field experiment takes place in a participant’s usual environment,such as at work or in their homes.This means their behavior is more likely to be natural/typically or how they act/respond in that setting.
What are the limitations of field experiments?
Less control over extraneous variables-more likely because researcher has less control.This means it is more difficult to establish a cause and effect relationship, as the results may be due to some other (extraneous) variable.
Harder to replicate -It is more difficult to repeat experiments that take place in a real life setting:there are more likely to be extraneous variables which cannot be controlled in the more naturalistic setting.This means that it is harder to repeat precisely in order to check the reliability (consistency) of the results.
How do you control artificiality?
Conduct in a natural environment-If participants take part in an experiment in their usual(natural) environment,using more realistic/naturalistic stimuli/tasks,they are more likely to produce ‘real’ behaviour. This means the results of the experiment are more likely to be valid.
How do you control experimenter effects?
Use a double blind condition-Here either the participants nor the researcher are aware which condition the participant is in.This reduces any expectations the participant or/and investigator may have about how the particpants behavior may be changed/affected by the condtion.
standardized instruction-This involves the experimenter using a standardised script to ensure consistency in what is said to each participant.This reduces the chance of of some participants/groups being given more/less information which might influence their behavior.
How do you control demand characteristics?
Deception-Misleading or withholding information from participants about the true aims of the experiment .Therefore,they are less likely to be suspicious or curious about the aims of the experiment meaning their real behavior is less likely to change.
Distractor tasks-Additional activities for the participants in order to reduce the chance of them guessing the true aim of the study.These additional activities are not analysed.
Use a single blind technique-Here the participant is not aware which condition they are in.This reduces any expectations they may have about how their behaviour may be changed/affected by the condition limiting this likelihood of demand characteristics.
What are the characteristics of natural experiments?
The IV has not been deliberately manipulated by the experimenter instead it is usually an (environmental/situational) event/change (to create the conditions of the experiment )
The DV may be naturally occurring or measured by the experimenter
Their is very little control over extraneous variables
As they often take advantage of the natural settings,situations or behaviors ,They tend to be more ecologically valid.
What are some examples of natural experiments in psychological research?
Williams research into the effects of the introduction of Tv(IV was before TV and after TV which was not introduced by the researcher)(Aggression/gender)
Rutlers Romanian orphan study(IV was the age at which the children were adopted.(attachment)
What are the strengths of natural experiments?
Improved ecological validity-This is because natural experiments often take place in a natural environment.This means the participants behavior is more natural/typical of how they behave normally,making the results more valid.This means the results can be generalized to real life/everyday behavior.
Very few demand characteristics-The environment is a familiar setting so they are unaware they are taking part in research and therefore are less conscious of their behaviour being observed .Thus,making it less likely for them to produce behaviours which they think the research is demanding making it more valid
Enables ethical research-in contary to other methods where the manipulation of the IV would be impractical, the experimenters take advantage of a naturally occurring situation or event (which would occur anyway)
What are the Limitations of natural experiments?
Causal conclusions not possible-Includes very little involvement/manipulation from the researcher.This means extraneous variables are not controlled including situational variables(as the environment is not standardized by the experimenter) and participant variables (as participants are not randomly allocated to groups).This means these other factors may be having the effect rather than the IV.Therefore,it is very difficult /impossible to draw cause and effect conclusions from natural experiments.
Very hard to replicate -Due to lack of researcher intervention,there is less standardization,meaning each situation and scenario is unique.This means that accurate replication is very difficult,therefore it is hard to know if the results are reliable(would occur again in the same way)
What are the characteristics of Quasi experiments?
The Iv has not been deliberately manipulated by the experimenter, instead the IV is based on an existing (participant) difference between people(To create the conditions of the experiment)This means that people cannot be allocated to conditions.
The DV may be naturally occurring or measured by the experimenter
They can take place in more natural (field) or lab based) settings.
What are some examples of Quasi experiments in psychological research?
-A comparison of males’ and females’ reaction time is a quasi experiment.Their sex is the IV as it is an existing difference between the participants.
Dare care research where the IV compares those children attending dare care with those raised at home .
Comparison of the effectiveness of CBT(cognitive behavioral therapy) between people with schizophrenia and depression(their mental health diagnosis is the IV)
What are the strengths of Quasi experiments?
Higher ecological validity-if the quasi experiment takes place in a naturalistic environment then the participants behaviour is more typical/natural of how they behave normally ,making the results more valid.This means the results can be generalized to real life behaviour
Enables research to be carried out to compare different groups of people,where manipulation of the IV (using other methods)would be unethical or impractical,as they take advantage of an existing difference.
What are the weaknesses of quasi experiments?
Casual conclusions not possible.In quasi experiments participant variables are an issue.As participants are not randomly allocated to groups ,other variables relating to the participants may be having the effect rather than the difference being investigated (the IV).This means it is very difficult/impossible to draw cause and effect conclusions from quasi experiments.
Very hard to replicate-(if conducted in a more usual/.natural setting)as there is usually less standardization. Therefore accurate replication is difficult and so its harder to know if the results are reliable.
What are repeated measure designs?
The same participants complete each condition of the experiment
E.g If a psyhcologist wanted to find out the effects of alcohol on a person’s driving ability-using two conditions each participant would complete both of the conditions(alchohol and no alcohol)so the two scores are related to the participant.
What is the data obtained from repeated measure designs?
Related data as each participant will provide two scores(one from condition A and one from condition B so the two scores are related the participant.
What is an independent measure design?
Different participants are used in each condition.
e.g in an experiment looking at the effects of loud music on memory ,two separate noises would be exposed to one of the two conditions (either noise or no noise)The participants are usually randomly allocated to either condition.
What is the data obtained from independent measure designs?
Unrelated data as the scores from each condition are obtained from two separate,unrelated,groups of participants.
What is matched pairs design?
Different partipants are used in each condition,but the participants are matched (prior to the experiment)on any important characteristics(participant variables)which may affect the results.
