research methods-experimental methods Flashcards
what is a theory
a coherent explanation of the relationship between two or more variables
what is an aim
the intended purpose for an investigation
why its being carried out
what the research investigation is actually trying to discover
what is a hypothesis
a precise testable statement which is a general prediction made at the beginning of an investigation about what the researcher expects to happen
what is the group where the IV happens
experimental group
what is the baseline comparison group called
control group
what is an operationalised variable
where the IV and DV are defined so that they can be measured
this will provide quantitative data
what is a positive of operationalizing variables
enables other psychologists to replicate your research to see if your results are reliable(consistent)
what is a negative of operationalizing variables
operational definitions tend to be fairly aribitary narrowing the scape of research
if a hypothesis it tested in an experiment its called
experimental hypothesis
what is a hypothesis tested in another method
alternative hypothesis
what is a directional (one tailed) hypothesis
predicts the direction the results are expected to occur
they are used when previous theory or existing research evidence suggests the findings of a study will go in a particular direction
EG-children who spend more than 20 hours a week in daycare WILL behave MORE aggressively than children who spend less than 20 hours a week
what is a non-directional (two-tailed) hypothesis
does not predict the expected direction of the results
its used when there is no reference to existing research evidence
EG-children who spend more than 20 hours a week in daycare WILL SIGNIFICANTLY DIFFER in how aggressive they are compare to children that spend less than 20 hours
what is a null hypothesis
no relationship between the variables
we reject the alternative hypothesis and accept our null hypothesis when the difference found is too small to be significant
EG- there will be NO SIGNIFICANT DIFFERENCE between the aggression scores for children who spend more than 20 hours a week in day care and those who spend less than 20 hours a week in daycare. ANY DIFFERENCE FOUND IS DUE TO CHANCE
what is a extraneous variable
any variable other than the IV that caused the change in the DV
what is a confounding variable
its an extraneous variable that hasn’t been controlled and has varied systematically with the IV and therefore affected the DV/results
what are the three examples of extraneous variables
situational
participant
experimenter
what is a situational variable
anything from the environment that could cause a change in the DV
they have to be RELEVANT to the experiment EG-if you were testing memory and some participants had to cope with more noise than other it might affect your results
they are controlled though standardization ensuring the only thing that differs between the two groups is the IV
what is a participant variable
-characteristics and differences to do with the individual taking part eg-age, gender, IQ, and experience
-eg-if you were testing driving behaviour and some of your participants were tired that may affect results
-they are controlled through experimental design eg-matched base pairs and by randomly allocating participants to conditions which helps reduce bias
what is a experimenter variable
-it refers to the expectation, appearance, behaviour, gender and personality type of the researcher that may influence the way a participant responds eg-female researcher asking a male participant for his attitude towards women
-they are subtle cues given by the researcher that can bias the outcome of the study
-the hawthorne effect is an example of an experimenter effect, this is where the presence of a researcher can affect the performance of the participant
how do psychologists ensure there experiment is valid
by eliminating or controlling any extraneous variables so they can be sure the IV affects the DV
what should you do with extraneous variables and why
eliminate them
impacts upon validity
how can unwanted variables result
from random or constant error
what is a random error
-participants state of mind
-motivation
-previous experience
-you can counteract this by random allocation of participants
what is a constant error
it can be eliminated by good experiental design eg-counterbalancing