experimental method Flashcards
experimental method
involves the manipulation of an IV to measure the effect on the DV. experiments may be laboratory, field, natural or quasi
aims
a general statement of what the researcher intends to investigate, the purpose of the study
- when the focus of the research has been narrowed down
- developed from theories
- general statements to describe the purpose of the investigation
variable
a variable is anything that is open to change
Independent variable
this is something that the researcher changes or manipulates
dependent variable
this is something that the researcher measures, to see if there has been change
operationalising variables
clearly defining variables in terms of how they are measured
hypothesis
this is a clear, precise, testable statement that predicts the outcome of a study
experimental hypothesis
this states that there is a significant difference between variables
directional hypothesis
this states that there is a significant difference between variables
non-directional hypothesis
this does not state the direction of the difference, psychologists use non-directional hypothesis when there is no previous research, or no findings from previous research are contradictory
null hypothesis
this states that there is no significant difference between variables
extraneous variable
this is any variable other than the IV that may have an effect on the DV if it is not controlled. This could include any change in environmental conditions, such as background noise or time of day
confounding variable
variables which systematically affect the dv, this can distort the role of the iv
demand characteristics
any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose/aim of the investigation; this may lead a participant to change their behaviour within the research situation. they may act in way that is expected and over-perform to please the experiment or they may deliberately underperform to sabotage the results of the study. either way participant’s behaviour is not natural
investigator effect
this is when the person collecting the data has knowledge of what the research aim is and that knowledge affects the data obtained (consciously and unconsciously). this may include the design of the study, the selection of participants or interaction with participants during the research process
standardisation
all participants should be subject to the same environment, information and experience. to ensure this, all procedures are standardised, so there is a list of exactly what will be done in the study. this also includes standardised instructions that are read to each participant. standardisation is an attempt to control for investigator effects as the researcher’s interaction with participants during the research process is controlled
randomisation
this refers to the use of change to make key decisions about how the experiment is conducted. random number generators, throwing a dice, flipping a coin. This is an attempt to control for investigator effects as this reduces the researcher’s influence of the design of an investigation
reliability
refers to how consistent the findings from an investigation or measuring device are. if a measurement/finding is repeated, then it is described as reliable
test-retest reliability
is a way of assessing the reliability of a questionnaire of psychological test, it can also be applied to intervews
inter-observer reliability
inter-observer reliability is a method of assessing the reliability of observations
validity
refers to whether a psychological test, observation or experiment produces a result that is genuine
internal validity
the extent to which the researcher is measuring what they intended to, so the effects observed in an experiment are due to the manipulation of the IV and not confounding variables
external validity
the extent to which the findings can be generalised beyond the research situation in which they were found
ecological validity
this is the extent to which the findings from a research study can be generalised to other settings and situation
temporal validity
the extent to which findings from a research study can be generalised to other historical times and eras
population validity
the extent to which findings from a sample can be generalised to the target population
