Experiments (1) Flashcards
Types of experiment
Laboratory, Field, Quasi
lab strengths (3)
.highly controlled
.manipulate the IV
.can be replicated
lab weaknesses (3)
.cant generalise to real life setting (lack of ecological validity)
.more effort/time/money
.participant may change behaviour
field strengths (4)
.cheaper
,ecologically valid
.easy to get sample
.higher internal validity
field weaknesses (3)
.lots of EVs
.participants may have different experiences
.hard to get consent (less ethical)
.harder to replicate
quasi strengths
.high ecological validity (IV not manipulated) so true to life
.helps us study variables we cant manipulate
quasi weaknesses (3)
.difficult to conduct
.cant control some participant variables
.cant be replicated
experimental designs
repeated measures design
independent measures design
matched participants design
repeated measures strengths
.reduces participant variables
.easier to get sample - less people
repeated measures weaknesses
.order effects
.demand characteristics
independent measures strengths
.no order effects
.reduced demand characteristics
independent measures weaknesses (2)
.participant variables
.more effort to collect sample
matched participants strengths (4)
.reduced participants variables
.no order effects
.lower chance of demand characteristics
.counterbalancing
matched participants weaknesses
.more effort to find people
.cant control all EVs by matching
participant variables
characteristics of an individual that may affect results e.g age, gender, experience
situational variables
features of the research that may affect results e.g order effects
environmental factors
factors of the environment that could affect results e.g weather
demand characteristics
cues in an experiment that communicate to participants what is expected of them and may unconsciously affect behaviour
alternative hypothesis
IV will affect DV
null hypothesis
IV wont affect DV
two tailed hypothesis
IV will have significant effect on DV, but does not say direction
one tailed hypothesis
IV will have significant effect on DV, and does say direction
sampling methods
self selecting
random
opportunity
snowball
self selecting strengths (2)
consent
easy to get participants
self selecting weaknesses (2)
not everyone may see advert
could be expensive
participant variables - all same type of person
random strengths (3)
no researcher bias
more likely to be generalisable
equal chance to be picked
random weaknesses (2)
equal chance to be picked could lead to anomalies
may have unwilling participants
opportunity strengths (2)
convenient (easy to obtain)
consent
opportunity weaknesses (2)
unrepresentative
researcher bias
snowball strengths (1)
easy to obtain
snowball weaknesses (2)
participant variables
cant generalise
ethical considerations (7)
informed consent (respect) right to withdraw (respect) confidentiality (respect) protection from harm (responsibility) debrief (responsibility) deception (integrity) only give relevant info (competence)
primary data
collecting data directly ourselves
secondary data
analyse already existing data
quantitative strengths (4)
easy to interpret
no researcher bias
easy to compare
establish reliability
quantitative weaknesses (2)
no reasoning
low ecological validity - may not represent everyday behaviour
qualitative strengths (2)
detailed
shows reasoning
qualitative weaknesses (3)
hard to compare
cant present in a graph/table
hard to analyse
measures of dispersion methods
range
variance
standard deviation
variance
score - mean score (d)
d squared
divide sum of d squared numbers by n-1
standard deviation
square root of the variance
single blind
participant doesn’t know true aims of study
double blind
participant and researcher don’t know true aims of study
internal reliability
was it standardised and replicable
external reliability
was sample large enough to be consistent?
internal validity
was it testing what it set out to?
external validity (population)
can the sample be generalised from?
external validity (ecological)
was it true to life?
longitudinal study strengths (3)
.controls participant variables
.measures change over time
.highly valid (population)
longitudinal study weaknesses (4)
.cant control some EV’s e.g upbringing
.time consuming
.drop out - need large sample
.expensive
cross cultural research strengths
.less ethnocentric
.investigates nature vs nurture
.generalise to larger population
cross cultural research weaknesses
.time consuming
.language barrier
.expensive
.more effort
ethical considerations - respect
informed consent
right to withdraw
confidentiality
ethical considerations - responsibility
debrief
protection from harm
ethical considerations - integrity
deception
ethical considerations - competence
only give relevant information