research methods - research issues

what is an extraneous variable ?

this is any variable other than the IV that may have an effect on the DV if it’s not controlled.

EVs are nuisance variables that do not vary systematically with the IV

if possible identify these at the start of the study to minimise their influence

what is a confounding variable ?

this is any extraneous variable that varies systematically with the IV. therefore we cannot tell if the change in the DV is due to the IV of the confounding variable

e.g. if the experimental condition saw prince harry on their way to school causing them to be more excited whilst the control group are less excited as they did not see him

what are demand characteristics

any cue from the researcher or from the research situation that may be interpreted by PS as revealing the purpose of the investigation. Leading to Ps changing their behaviour withing the research situation - cause (the please u effect) or (screw you effect )

this could cause extraneous variables that may effect the DV

What are investigator effects

any effect of the investigator’s behaviours (conscious / unconscious)bon the research outcome DV - This could include everything from the design of the study to the selection of, and interaction with the PS during the research process

What did Hugh Coolican point out (investigator effects)

investigator effects can also include expectancy effects and unconscious cues i.e. smiling more when a Ps exhibits a behaviour or having leading questions or selecting Ps, material or instructions that maybe biased

what is randomisation ?

the use of chance methods to control the effects of bias when designing materials and deciding the order of experimental conditions

e.g. if a Ps is recalling words the order of the words should be randomly generated so that the positions of each word isn’t chosen by the researcher

what is standardisation ?

using exactly the same formalised procedures and instructions for all participant in the study

this means that as far as possible all Ps should be subject to the same environment, information and experience.

standardisation means that non-standardised changes in variables in procedure do not act as extraneous variables