Research Methods - Experiments types and designs Flashcards
what is an experiment
type of research method which collects data in a controlled setting where the researcher manipulates the IV and measures its effect on DV.
Strengths of Lab experiments
- High levels of Control
- Easily replicated
explain strength of lab experiments - high levels of controls
high level of control over the research environments by controlling extraneous variables allowing the researcher to be confident about establishing a casual relationship between IV and DV increasing the validity of the study
Explain the strength of lab experiments - easily replicated
they can be repeated by other researchers as they can replicate the same conditions and follow the standardised procedures to see whether they obtain similar results. if the results are similar this increases the internal validity and reliability of the study,
what are the two weaknesses of lab experiments
- may lack generalisability
- demand characteristics
explain the weakness of lab experiments - may lack genralisibilty
critised for being artificial and the participants are aware of being studied . this means their behaviour is not natural and therefore the findings cannot generalise to the real world therefore lab experiments have low external validitiy.
explain the weakness of lab experiments - demand characteristics
demand characteristics are cues (e.g videos /tasks) that might indicate the study aims to participant. cues can lead particpants to chanege their behaviors and unconsioncly respond to such cues rather than the effect of the IV. this will reduce the validity of the finidings.
what is a field experiment
type of research method which collects data in a natural setting. the researcher manipulates the iv and measures and record the dv . in a field experiment they are usually not aware they are taking part in the study.
strength of field experiments
- more natural environments
- high external validity
explain the strength of field experiments - more natural environment
- more natural environment (participants in their normal situation are likely to behave in representative wat - how they usually would behave. this means the results may be more generalisable to everyday life.
explain the strength of field experiments - high external valdity
field experiments are conducted in the real world where the participants are often not aware they are taking part in a study. this means that findings are often more realistic and true to life than lab experiments and therefore they are high in external validity.
field experiments weaknesses
more difficult to control unwanted variables
ethical issues
explain the weakenss of field experiments - more difficult to control unwanted variables
the researcher has less control over the natural environment the means changes to dv may not be due to iv but to other unwanted variables cv. this makes it more difficult to establish a cause and effect relationship wich reduces the validity of the research and findings.
explain the field experiment - ethical issues
participants in a field experiment may not have given informed consent. this is an invasion of privacy which raises ethical issues.
what is a natural experiment
a type of research method which collects data from a situation where the researcher does not manipulate the IV. This is because the IV would have changed/occurred by itself - naturally occurring.
for a natural experiment where is the DV measured
in a laboratory or in the field. the key feature of natural experiment is not where it is conducted but the way the independent variable is manipulate
- e.g a study that compares football players to rugby players (IV varies naturally). the DV could be the IQ test in a controlled lab setting
strengths of natural experiments
- only ethical option
- greater external validity
weaknesses of natural experiment
- the natural event may occur rarely
- participants are not randomly assigned
explain the strength of natural experiments - only ethical option
natural experiments allow the psychologists to investigate the phenomena that would be unethical to manipulate the IV. e.g a researcher investigating the effects of teenage smoking cannot randomly assign people to groups of smokers and non smokers to see whether they develop cancer. this means a natural experiment may be the only way to research a topic.
explain the strength of natural experiments - greater external validity
natural experiments often involves real life issues such as the effects of institutionalisation on children,stress. this means the findings are more relevant to real life situations.
explain the weakness of natural experiments - the natural event may occur rarley.
many natural events only occur once in unique situations and this reduces the oppurtunity for more research investigation. this means this will limit the scope for generalising findings to other similar situations.
explain the weakness of natural experiments - participants are not randomly assigned
The experimenter has no control over which participants are placed in which conditions as the IV is pre-existing. This may result in variables that are not controlled which will affect the IV. For example, roman orphan adopted early may also be the friendlier ones. this reduces the validity of the findings.
What is a Quasi experimetns
in a quasi experiment the participants are not assigned randomly to the experimental and the control group. this is because the IV is pre existing before the experiment took place which means the researcher cannot manipulate the IV.
why is there no control group in a quasi experiment
there is no control group just a comparison between the two different groups. for example testing difference in memory recall between gender. the iv is gender. the researcher cannot manipulate gender it is pre-existing. male will be on condition and females be in another condition.
what is the difference between natural and quasi expeiments
the difference between natural and quasi experiment is to see if the IV can be manipulated. it is not possible to do this in a natural experiment but it is to do that with a quasi experiment.
strengths of quasi experiments
- comparison can be made
- high control
weakness of quasi experiments
- partcipants are not randomly assigned
- cause-effect relationship cannot be guaranteed.
weakness of quasi experiments
- partcipants are not randomly assigned
- cause-effect relationship cannot be guaranteed.
explain the strength of quasi experiments - comparison can be made
quasi experiments allow psychologist to study the differences in people (gender, autism,ethnicity,e.t.c). this means that comparison between different types of people or behaviors can be made.
explain the strength of quasi experiments - comparison can be made
quasi experiments allow psychologist to study the differences in people (gender, autism,ethnicity,e.t.c). this means that comparison between different types of people or behaviors can be made.
explain the strength of quasi experiments - high control
quasi experiments are often carried out in controlled conditions which makes it easy for other to replicate the study to see if similar results are foung. this means we are more confident in drawing a causal conclusions (cause and effect realationships between the IV and DV). this increase the validity of the findings.
explain the weakness of quasi experiments - participants are not randomly assigned.
in a quasi experiment there is no random allocation this means the researcher has no control over which participants are placed in which conditions as the IV is pre-existing. this means participant variables, may act as a confounding variable as this might have caused the change in DV. therefore we cannot be confident in inferring a cause and effect relationship.
explain the weakness of quasi experiments - cause and effect relationship cannot be guaranteed.
the researcher does not manipulate or control the IV. this means we cannot be certain that any changes in the DV was due to the IV. therefore cause and effect may not be guaranteed that it occured.
