experimental design Flashcards
independent groups design
participants only perform one condition of the independent variable
independent strengths
no order effects presented
participants are less likely to guess the aims of the study - demand characteristics eliminated
independent limitations
no control over participant variables
- different abilities of participants in the various conditions can cause changes to the DV
may need more participants than other designs
independent solution
random allocation - solved lack of control - ensures that each participant has the same chance of being in one condition of IV as another
repeated measures
the same participants take place in all conditions of the IV
repeated measures strengths
eliminates participant variables
fewer participants needed, so not as time consuming finding and using them
repeated measures limitation
order effects presented - boredom, fatigue - second condition - participant does not do as well on task
repeated measures solution
counterbalancing - half of participants do conditions in one order and other half in opposite order
matched pairs
pairs of participants are first matched on some variable that has been found to affect the dependent variable then one member of each pair does one condition and the other does another
matched pairs strength
no order effects
demand characteristics less of a problem
matched pairs limitation
time consuming and expensive to match participants
large pool of potential participants is needed which can be hard to get
difficult to know which variables are appropriate for the participants to be matched
pilot study
small-scale version of an investigation which is done before the real investigation is undertaken - allow potential problems of the study to be identified and the procedure to be modified to deal with these
- allows money and time to be saved in the long run.
single-blind procedure
a researcher method - researcher do not tell the participants they are being given a test treatment or a control treatment - avoids demand characteristics
double-blind procedure
neither the participants not the experimenter knows who is receiving particular treatment - prevent bias
naturalistic observation
watching and recording behaviour in the setting where it would normally take place
naturalistic strengths
high ecological validity
high external validity as done in a natural environment
naturalistic limitations
low ecological if participants become aware they are being watch
replications difficult
uncontrolled confounding and extraneous variables are presented
controlled observation
watching and recording behaviour in a structured environment
eg lab setting
controlled obv strengths
- researcher is able to focus on a particular aspect of behaviour
- more control over extraneous and confounding variables
- easy replication
controlled obv limitations
more likely to be observing unnatural behaviour as takes place in an unnatural environment
low mundane realism so low ecological validity
demand characteristics presented
overt
participants are watched and their behaviour is recorded with them knowing they are being watched
overt strengths
ethnically acceptable as informed consent is given
overt limitations
more likely to be recording unnatural behaviour as participants know they are being watched
demand characteristics likely which reduces validity of findings
covert
the participants are unaware that their behaviour is being watched and recorded
covert strengths
natural behaviour recorded hence high internal validity of results
removed problem of participant reactivity whereby participants try to make sense of the situation they are in - less likely to guess the aim
covert limitation
ethical issues presented as no informed consent given
could also be invading the privacy of participants
participant observation
the researcher who is observing is part of the group that is being observed
participant strength
can be more insightful which increases the validity of the findings
participant limitation
possibility that behaviour may change if the participants were to find out they are being watched
researcher may lose objectivity as may start to identify too strongly with the participants
non-participant observation
the researcher observes from a distance so is not part of the group being observed from a distance is not part of the group being observed
non-participant strength
researcher can be more objective as less likely to identify with participants
non-participant limitation
open to observer bias for example of stereotypes the observer is aware of
researcher may lose some valuable insight
unstructured observation
consists of continuous recording where researcher writes everything they see
unstructured obv strength
more richness and depth of detail
unstructured obv limitations
produces qualitative data is more difficult to record and analyse
greater risk of observer bias
structured obv
researcher quantifies what they are observing using predetermined list of behaviours and sampling methods
structured obv strengths
easier as is more systematic
quantitative data is collected which is easy to analyse and compare with other data
less risk of observer bias
structured obv limitations
not much depth of detail
difficult to achieve high inter observer reliability as filling predetermined lists in is subjective
time sampling
recording of behaviour within a timeframe that is pre-established before study
- reduces number of observations so less time consuming
- small data within frame so unrepresentative
event sampling
involves the counting of the number of times a particular behaviour is carried out
- good for infrequent behaviours that are likely to be missed if time sampling used
- complex behaviour, important details may be overlooked
- if very frequent then counting errors
