Experiments: type and design Flashcards
what is the definition of lab experiments?
a highly controlled research method where the research controls environmental factors to observe the effect of the independent variable on the dependant variable
what are the key features of lab experiments?
-standardised procedures ensure replicability and reliability
-all variable constant except the IV
-conducted in the same space with controlled light, heat, sound, and consistent researcher behaviour
what are the strengths of lab experiments?
-easier to establish cause-effect relationships
-high internal validity due to control
-replicable, increasing reliability
what are the limitations of lab experiments?
-artificial tasks reduce ecological
-findings may not generalise to real-world setting
-demand characteristics can alter participants behaviour, reducing external validity
what is the definition of field experiments?
-field experiments are conducted in natural settings with less control over variables
-included IV and DV e.g ‘kindness’ programmes effect on prosocial behavioural
what are the key features of field experiments?
-real-world distractions (e.g weather, noise) acts as extraneous variables
-can collect both quantitative and qualitative data
what are some strengths of field experiments?
-high external validity due to natural setting
-participants behave more naturally, reducing demand characterisitics
what are some limitations of field experiments?
-extranous variables may interfere with results
-harder to replicate, reducing reliability
-lower control reduces internal validity
what is the definition of natural experiments?
-study of naturally occurring phenomena
-no manipulation of IV or random allocation of participants
what are key features of natural experiments?
-conducted in participants natural settings
-qualitative data e.g interviews about personal experiences
what are some strength of natural experiments?
-ethical way to study sensitive topics
-high ecological validity due to real-world settings
-first-hand participants reports enhance mundane realism
what are some limitations of natural experiments?
-casual relationships are hard to determine
-relies on subjective participants accounts, reducing reliability
-prone to biases (e.g social desirability, confirmation, sample bias)
what is the definition of quasi-experiments?
where the IV is naturally occurring (e.g age, gender) and participants are not randomly assigned to conditions
what are the key features of quasi experiment?
-collect quantitative data using experimental designs
-lack full researcher control over IV
what are the strengths of quasi experiments?
-high external validity due to natural IV
-can provide useful insights (e.g age and memory)
-replicable with demographically similar participants
what are the limitations of quasi experiments?
-lack of random allocation leads to participants variables
-less reliable than true experiments
-may lack internal validity due to uncontrolled factors
what are the three types of experimental design?
independent groups, repeated measures, matched pairs
what is the definition of independent group design?
where the participants experience only one condition of the IV and data is unrelated since different groups provide separate data sets
give an example of independent group design
-group A: learns a poem with music
-group B: learns the same poem in silence
-Dv: number of words recalled in 5 minutes
in independent group design, how do they allocate participants?
random allocation, where participants are randomly assigned to conditions to avoid researcher bias (e.g drawing names from a hat)
what are strengths of independent group design?
-reduces demand characteristics (participants don’t guess study aim)
-eliminates order effects like fatigue or practise
what are limitations of independent groups design?
-participant variable may affect result (uneven skill levels)
-requires more participants, which can be logistically difficult
what is repeated measure design?
-participants experience all conditions of the IV
-data is related since participants act as their own control group
what is an example of repeated measure design?
-particpant learns a poem with music (condition one) and another poem in silence (condition two)
-Dv: words recalled in each condition compared
how does repeated measure design split participants?
through counterbalancing, the participants are split into two groups:
-group 1: condition A then B
-group 2: condition B then A
what are strengths of repeated measure design?
-controls participant variables (same people in all conditions)
-requires fewer participants, making it easier to organise
what are some limitations of repeated measure design?
-may lead to demand characteristics (participants guess the study’s aim)
-order effects (fatigue, boredom or practise) could affect results
what is matched pairs designs?
-where participants are matched on important characteristics (e.g age, IQ, aggression)
-each pair split between conditions
give an example of matched pair design
e.g participants patched by aggression level
-person A: condition 1
-person B: condition 2
what are some strengths of matched pair design?
-control participant variable (matches participants on key traits)
-reduces demand characteristics ( participants tested only once)
what are limitations for matched pairs design?
-time consuming to find matched
-perfect matches are difficult, affecting reliability
-dropouts disrupt the research process
