define an extraneous variable
Any variable other than independent that may affect the dependent variable it not controlled- nuisance variables which dont vary systematically
confounding variables
A kind of extraneous variable but key feature is that it varies systematically with the independent therefore can’t tell if any change in dependent variable is due to independent or confounding variable
Demand characteristics
Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation, may lead to a participant changign their behaviour within the research situation
Investigator effects
Any (unintentional) influence of the researcher’s behaviour/characteristics on participants/data/outcome.
Situation variables
features of the environment (e.g. temperature, background noise) which may influence the outcome of the study
social desirability bias
A tendency for respondents to answer questions in such a way that presents themselves in a better light
particiapanst variables
Any individual differences between participants that may affect the dependant variable
randomisation
use of chance methods to control for the effects of bias when designing materials and deciding order of conditions
standirdisation
Using exactly the same formalised procedures and instructions for all participants in a research study
single-blind design
When the participant in the study is not told the aim of the research, other details also may be hidden such as which condition of the experiment they’re in or whether there is another condition at all, information that migth create expectations not revealed until end of study to control the confounding effects of demans characteristics
double-blidn design
Neither the participant nor the researcher who conducts the study is aware of the aim of the investigation (3rd party conducts investigation), often used in drug trials
extraenous variable
a variable that does not vary systematically with the independent variable but may have an effect on the dependent variable. They make it difficult to detect cause and effect (i.e. that it was your independent variable that caused your dependent variable and not anything else).
* They are variables that might affect the dependent variable and so need to be controlled.
confounding variables
a variable that is not the independent variable but does vary systema variable that is not the independent variable but does vary systematically with the IV. Changes in the dependent variable may be due to the confounding variable rather than the IV and therefore the outcome is meaningless.atically with the IV. Changes in the dependent variable may be due to the confounding variable rather than the IV and therefore the outcome is meaningless.
* They are variables that were not controlled in the study and so have affected the results.
how do u explain confounding/extraneous variables about cause and effect
how can you overcome extrneous/confoudnign variables
how can u overcome investigator effects
def of experimental methos
Involves the manipulation of an independent variable to measure the effect on the depend variable
def of lab experiment
An experiment that takes in place in a controlled environment within which the researcher manipulates the IV and records the ffect on the DV, whilst maintaining strict control of extraneous variables
def of a field experiemnt
An experiment that takes place in a natural settign within which the researcher manipulates the IV and record the effect on the DV
def of a natural experiemnt
An experiment where the change in the IV is not brought about by the researcher but would have happened if the researcher had not been there. The researcher records the effect on a DV they have decided on
def of a quasi expeiment
when the IV is a naturally-occurring difference between the participants
strength of lab experiments
weakness of lab experiment
strength of field experiments