Controlled Experiments Flashcards
1
Q
what is a controlled experiment?
A
- it’s when a hypothesis is scientifically tested
- any EVs= controlled
- the researcher can OPERATIONALISE (i.e. define) the variables being studied so that they can be objectively measured
- the QUANTITATIVE DATA can be analysed to see if there’s a difference between the EG & CG
2
Q
what happens to the DV & IV?
A
- IV: systematically manipulated
- DV: measured
3
Q
IV & DV
A
IV (cause) influences the DV (effect)
4
Q
Control Group
A
- in experiments scientists COMPARE a CG & an EG that are IDENTICAL in all respects
- unlike the EG, the CG is NOT exposed to the IV under investigation and so provides a BASELINE against which any changes in the EG can be compared
5
Q
Random allocating
A
RA participants to IV groups means that ALL participants should have an equal chance of taking part in EACH condition
6
Q
Extraneous Variables
A
- the researcher wants to ensure the manipulation of the IV has caused the changes in the DV
- hence, all the OTHER VARIABLES that could affect the DV to change must be CONTROLLED-these are called either EVs/ CVs
- EVs should be controlled whenever possible, as they might be wichtig enough to provide ALTERNATIVE explanations for the effects
7
Q
EV example
A
Caffeine (IV) influences no of words recalled (DV)
other variables:
- time of day (controlled by all tested @ 9am)
- tea/ coffee intake (controlled by NO caffeine 12hrs prior)
- noise (controlled by a quiet environment)
8
Q
Problems w/ trying to control EVs
A
- in practice, it’d be hard to CONTROL ALL the variables on kid’s educational achievements- it would be hard to control variables that have happened in the PAST
- you can only control the CURRENT ENVIRON of participants, such as: time of day & noise levels
9
Q
Why use controlled experiments?
A
- scientists used them as they allow for PRECISE CONTROL of EVs & IVs- allows a C&E relationship to be est
- they also follow a STANDARDISED step-by-step procedure= makes it easy for REPLICATION
