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
how do you conduct counterbalancing
half the participants do condition A followed by condition B and the other half do vice versa
what is counterbalancing
counterbalancing is a technique used to deal with order effects when using a repeated measure design
how do you avoid confounding variables
by holding theme constant
eg-if you think time of day may be relevant to your study make sure all participants were tested at the same time of day
how do you control extraneous variables
randomization-this is when trials are presented in a random order to avoid any bias
standardization-keeping the procedure the same
what is a single blind procedure
this is when the participant’s do not know the hypothesis and do not know which condition they are in in the experiment
what is the purpose of a single blind procedure
so participants don’t show demand characteristics which in turn improves validity
what is a double blind procedure
where both the researcher and participant don’t know the hypothesis and what condition they are in
what is the purpose of a double blind procedure
reduces researcher bias
what is a research method
the research method refers to the way in which psychologists go about collecting their data
what are the 4 types of experimental methods
-laboratory
-field
-natural
-quasi
what is a laboratory experiment
-takes place under highly controlled conditions
-the Iv is manipulated and all other variables are controlled so we can see the effects of the manipulation on the DV
-a common design is to have an experimental (does something) and control condition (doesn’t do anything)
-the control condition provides a baseline measure-what the dependent variable would be like without any manipulation
-participants may be aware they are taking part in an experiment due to the contrived nature of the situation
-they have random allocation of participants to conditions