Research Methods
Experimental Method
Aims
An aim is a general statement of what the researcher intends to investgate; i.e. the purpose of
the study
o E.g. to investgate whether energy drinks make people more talkatve
The aim should include a general statement of why the research is taking place, what is being
studied and what the study is trying to achieve
Hypotheses
Hypothesis: a clear, precise, testable statement that states the relatonship between the
variables to be investgated. It is stated at the outset of a study
o Experimental hypothesis: predicts a significant diference in the dependent variable as a
result of the manipulaton of the independent variable
o Null hypothesis: predicts no significant diference in the dependent variable as a result
of the manipulaton of the independent variable. It simply suggests your results could
have occurred by chance
A directional hypothesis indicates which way the dependent variable will change
o This is used when findings from previous research suggest a partcular outcome
A non directional hypothesis suggests that there will be a diference but that the diference
could be either an increase or a decrease in the DV
o This is used when there is no previous research, or previous research is contradictory
A hypothesis should include:
o The IV (both conditonss and the DV
o Operatonalisaton of variables
Operationalisation: clearly defining variables in terms of how they can be
measured
E.g. “blondes are really dumb” would have an operatonalised IV of ‘diferent hair
colours from a hair colour chart (natural hair onlys’ and a DV of ‘level of intelligence
from IQ test’
o Directonal or non-directonal
o The word ‘significant’
Directonal example: People who *IV first conditon* do significantly beter at *DV* than people
who *IV second conditon*
Non-directonal example: There is a significant diference in *DV* between people who *IV first
conditon* and people who *IV second conditon*.
Null hypothesis examples:
o There is no significant diference in *DV* between people who *IV first conditon* and
people who *IV second conditon*. Or…
o Any diference between *IV first conditon* and *IV second conditon* when *DV* is
due to chance.
Correlatonal examples:
o There is a significant positveenegatve correlaton between variable A and variable B
o There is a significant correlaton between variable A and variable B