experiments Flashcards
advantages lab experiments
reduced effects of extraneous variables so higher internal validity
can be replicated with participants being compared
disadvantages of lab experiments
low ecological validity as settings cannot be generalised to real life
more effort time and money to conduct research
advantages of field experiments
high ecological validity as natural setting
less effort to set up and conduct
disadvantages of field experiments
higher change of extraneous variables influencing events
participants may have different experiences so lowering internal reliability
what is a quasi experiment
The IV is naturally occurring not manipulated by the researcher
What is a lab experiment
the IV is manipulated and experiment carried out in a contrived setting
what is a field experiment
the IV is manipulated and experiment carried out in normal surroundings
advantages of quasi experiments
high ecological validity as IV not manipulated
help us to study variables that we cannot manipulate
disadvantages of quasi experiments
difficult to conduct in some situations
cannot control some participants variables that may influence the results
three experimental designs
-repeated measures designs (using same participants)
-independent measures design (using different participants)
-matched participant design
evaluation of repeated measures design
a: removes effect of participant variables, easier to obtain sample
d: demand characteristics, order effects
evaluation of independent measures design
a: reduced demand characteristics, no order effects
d:larger sample needed, participant variables may influence findings
evaluation of matched participants design
a:reduced effect of participant variables, no order effects, lower chance of demand characteristics
d:larger sample needed, cannot control all extraneous variables
what is an alternative hypothesis
a hypothesis that predicts how the IV will affect the DV
what is a null hypothesis
a hypothesis that predicts that the IV will not have an effect on the DV
what is a 2 tailed hypothesis
a hypothesis that does not predict the direction the IV will have on the DV
what is a one tailed hypothesis
a hypothesis that does predict the direction the IV will have on the DV due to the existence of prior research
4 types of sampling methods
self selecting, opportunity, random, snowball
what are the 4 ethical principles
Respect
competence
responsibility
integrity
what principles does respect include
informed consent, right to withdraw, confidentiality
what is competence
the need for psychologists to work within their own capabilities
what principles does responsibility include
protection
debrief
what does integrity principle include
deception
what are the 3 measures of central tendency
mean, mode, median
how to work out variance+ standard deviation
calculate the mean score of each condition
subtract the mean score from each participants score to get d
square each d score
add all to get the sum of d squaresed
divide this figure by (n-1)
standard deviation= square root of variance
