experimental method Flashcards
what are the aims of an experiment
aims are developed from theories
They are general statements that describe the purpose of an investigation
what is hypothesis
a hypothesis is a statement that is made at the start of a study and clearly states the relationship between the variables as stated by the theory
a hypothesis can be directional or non - directional
what is a directional hypothesis
the researcher makes clear the sort of difference that is anticipated between two conditions or two groups of people
for this reason directional hypothesis includes words like less, higher or lower, faster or slower
e.g. people who drink speed up become MORE talkative than people who don’t
what is a non - directional hypothesis
a non directional hypothesis simply state that there is a difference between the two conditions or groups of people, but unlike in a directional hypothesis, the nature of the difference is not specified
e.g. People who drink speed up differ in terms of talkativeness compared with people who don’t drink speed up
when is a directional hypothesis used
a directional hypothesis is used when the findings of previous research suggests a particular outcome
when is a non directional hypothesis used
when there is no previous research, or findings from earlier studies are contradictory
what are the different variables in an experiment
in an experiment, a researcher changes or manipulates the independent variables (IV) and records or measures the effect of this change on the dependent variables (DV)
All variables that potentially affect the DV should remain constant in a properly run experiment. This is so researchers can be confident that the cause on the DV was the IV and the IV alone
what are the different levels of IV
to test the effect of the IV we need different experimental conditions e.g.
If we simply gave some participants SPEED UPP, how would we know how talkative they were. Therefore we need a comparison- compare participants’ talkative levels before and after drinking SPEED UPP
In either case, the two conditions are no SPEED UPP or drinking SPEED UPP.
These are the two levels of the IV: the control condition (no SPEED UPP) and the experimental condition (energy drink)
what does it mean when we say that we have to operationalise variables
researchers make sure that the variables being investigated are measurable as possible
e.g. The group that drink energy drink will be chattier than the group that drinks water
after being operationalised this hypothesis becomes:
After drinking 300ml of SPEED UPP participants say more words in the next five minutes than participants who drink 300ml of water
