RM: Experimental and Non-experimental Methods + Validity and Reliability Flashcards
name the different types of experimental method
lab experiment
field experiment
natural experiment
quasi experiment
what is typically involved in a lab experiment?
- empirical, observable measurements are made
- highly controlled setting where the independent variable is manipulated and the dependent variable is measured
what is an extraneous variable
a variable other than the independent variable that may affect the dependent variable, and the results of the study, and their validity
what is a confounding variable?
a variable that varies systematically with the IV and influences the supposed cause and effect
how can we overcome confounding variables?
randomisation of participants and using standardised techniques
what is an aim?
a statement about the purpose of research and why it is being carried out
what is a hypothesis?
a clear, testable statement that allows the researcher to predict the outcome of an investigation
what is a directional hypothesis?
a statement that predicts the direction of the difference
when do we use a directional hypothesis?
when there has been previous research carried out into the topic
what is a non-directional hypothesis
a statement that does not predict the outcome of the difference
when do we use a non-directional hypothesis?
when there has been no previous research on that topic
what is a null hypothesis?
a statement that predicts no direction of the outcome (no significant difference/correlation)
when is a null hypothesis used?
a researcher will always write a null hypothesis at the beginning of the study, along with their directional/non directional hypothesis, depending on whether there has been previous research into that area or not.
what is a demand characteristic?
cues in an experimental situation that help participants guess the aim of the study. as a result, participants change their behaviour, and are no longer behaving naturally.
how can we overcome demand characteristics?
using single and double blind procedures.
single = participants are unaware of the research aims and hypothesis, and do not know which condition they are in
double = both the researcher and the participant are unaware of the condition and the aims/hypothesis.
what are the strengths of lab experiments?
- they are highly controlled, so cause and effect can be established between the independent variable and the dependent variable
- they use a standardised procedure, which allows the experiment to be easily replicated by others to check the reliability of the findings
what are the weaknesses of lab experiments?
- participants can respond to demand characteristics and so exhibit behaviour that is not typical of their normal behaviour
- low ecological validity as the environment is highly artificial so findings cannot be generalised to everyday situations.
what are demand characteristics?
when participants change their natural behaviour to act in line with their interpretation of the aims of the study
what is validity?
whether a measure actually measures what it claims to be measuring
what are the 7 types of validity
ecological validity
temporal validity
population validity
concurrent validity
internal validity
face validity
external validity
what is internal validity?
the extent to which the results of the experiment are due to manipulation of the independent variable (whether the experiment measured what it was supposed to)
what are the two types of external validity
ecological validity and population validity
what is population validity?
the extent to which findings can be generalised to wider populations.
what is ecological validity?
the extent to which the findings of the study can be generalised to real life. eg. if study was conducted in a lab, this is a very artificial setting that is dissimilar to real life, so study has low ecological validity. or if the study investigated how many shocks a participant would give to a confederate, this is a situation very unlikley to take place in real life, so study has low ecological validity.
what is concurrent validity?
the extent to which the results of the study concur with other studies and evidence. (comparing a new test to an already existing test)
what is temporal validity?
the extent to which the findings of a study are valid when differences and progressions that come with time are considered
what is face validity?
the extent to which a study APPEARS to measure what it claims to measure. eg. how logical is the data collection method/independent variable?
what is reliability?
a measure of whether findings are consistent with studies carried out previously
what are confounding variables?
a type of extraneous variable that varies systematically with the independent variable and so is difficult to control for
what is a field experiment?
an experiment that takes place in a natural everyday setting, but the IV is still manipulated and the DV is still measured
what are the strengths of a field experiment?
- have a higher ecological validity than lab experiments due to the natural environment - findings are easier to generalise to real life
- participants are less likely to respond to demand characteristics as they are often unaware they are participating in a field experiment
what is a natural experiment?
- an experiment that takes place in a natural setting, but the IV is not manipulated - it already exists (researcher collects data from something that would have happened anyway)
what are the strengths of natural experiments?
- have high ecological validity as they take place in natural settings
- participants are less likely to respond to demand characteristics as they are unaware they are participating in the study
what are the weaknesses of natural experiments?
- its not possible to control for or eliminate extraneous variables that may have an impact on the DV - so more difficult to establish cause and effect between the IV and the DV
- difficult to replicate as there is a lack of control over the extraneous variables
what is a quasi experiment?
experiments that have an IV based on existing differences between people - the IV is not manipulated, it simply exists
what are the strengths of quasi experiments?
- often carried out under controlled conditions and so have the same strengths as lab experiments
- sometimes carried out in more natural environments and so have the same strengths as field and natural experiments
what are the weaknesses of quasi experiements?
- the two groups being tested may differ in more important ways than the difference being measured - other confounding variables may be present
- if experiment takes place in a lab we can say the participants are prone to demand characteristics
what is external validity?
what are the two types of external validity?
the extent to which findings can be generalised to the real world
there are two types : ecological validity and population validity
what are the 3 different types of non-experimental method?
observations
self report methods
correlations
what are the different types of observation?
- naturalistic and controlled
- covert and overt
- participant and non-participant
what is a naturalistic observation?
an observation carried out in a natural setting, in the participants own environment, and interference is kept to a minimum
what are the strengths of naturalistic observations?
- high ecological validity as it takes place in a natural environment, so findings can be generalised to other real life settings
- allows researcher to study behaviour that cannot be manipulated in a lab due to ethical concerns
what are the weaknesses of naturalistic observations
- difficult to establish cause and effect because you cannot control for extraneous variables
- difficult to replicate under the exact same conditions
what is a controlled observation?
observations that take place in controlled laboratory environments.
what is a strength of using controlled observations?
- due to high control over variables and standardised procedure they are very easy to replicate, so easier to check the reliability of the findings
- also, extraneous variables can be eliminated
what are the weaknesses of controlled observations
- higher chance of participants responding to demand characteristics as they are in an artificial environment and they know they are being observed
- also, due to artificial environment, controlled observations have low ecological validity, so its not possible to generalise findings to real life situations
what are covert observations
when an observation is done secretly and a participant is being observed without their knowledge
what are the strengths of covert observations
- as participant is unaware they are being observed, they will act naturally, so there are no demand characteristics
- allows researcher to observe behaviour that is done in private
what are the weaknesses of covert observations
- ethical issues as there is no informed consent
- difficult to observe behaviour without being discovered
what are overt observations
when an observation is done openly and the participant is aware they are being observed
what are the strengths of overt observations
as the participant knows they are being observed the researcher can find out more information from them after the observation
- fewer ethical issues than covert observations as participant can give informed consent
what is a weakness of overt observations
- as participant knows they are being observed they may respond to observer effects or investigator effects which lead to demand characteristics
what is a participant observation
when the observer is involved and participates in the behaviour of the group being observed
what is a strength of participant observations
- as the observer is fully immersed in the behaviour of the group, they have a fuller understanding of the action of the group being observed
what is a weakness of participant observations
as the researcher becomes fully immersed in the behaviour of the group, it may be difficult for them to remain objective
what are non- participant observations
when the researcher follows the group around during the activities but does not engage in them
what are the strengths of non-participant observations
- the researcher is not interfering with the behaviour being observed
- researcher is able to remain objective
what are the weaknesses of non-participant observations
- researcher may not fully understand the actions of the group
- participants may respond to observer/investigator effects
how is behaviour recorded during observations?
using behavioural categories
- note taking and udo/video recordings can also be used
what does using behavioural categories entail?
- a behaviour checklist, so that every time a behaviour is observed, a tally is put into the appropriate cell on the table.
what is a strength and a weakness of using behavioural categories during observations?
strengths = the tallies make the data easier to quantify and use in graphs compared to qualitative data.
behavioural categories are also classed as a more scientific and objective way of carrying out observations compared to other methods of observation as it is a standardised technique which makes it easier to replicate and check for reliability
weaknesses = one observers definition of a certain behaviour may be different to another observers definition. this may mean that different results are obtained by two different observers. this is called a lack of inter-observer reliability.
what is time sampling and why is it used?
what is a strength/weakness of it?
- when behaviour is observed at different intervals of time, such as one hour observing one hour not observing.
- this is done because it is not possible to observe every moment of a group/p’s life, so a systematic approach is needed.
- a weakness of it is that it could miss important behaviours.
- a strength of it is that it reduces the number of observations that need to be made.
what is event sampling and what is a strength of it?
- when the researcher focuses on a specific, pre selected behaviour that they are interested in and records it every time it occurs.
- a strength of this is that it is useful when an event happens infrequently, so could be missed with time sampling.
what are investigator effects and how can they be reduced?
when the researcher unintentionally influences the outcome of a study eg. by unintentionally acting in a way to support their prediction.
double blind studies, standardisation, random allocation
