extraneous/confounding variables

Question 1

extraneous variable

Answer 1

any variable, other than the independent variable, that may affect the dependent variable if not controlled. They are nuisance variables that do not vary systematically with the IV

Question 2

confounding variable

Answer 2

a kind of EV but the key feature is that it varies systematically with the IV. Therefore we cant tell if any change in the DV is due to the IV or the confounding variable

Question 3

demand characteristics

Answer 3

any clue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of an investigation. This may lead to a participants changing their behaviour

Question 4

investigator effect

Answer 4

any unintentional influence of the investigator’s behaviour on the research outcome (DV). This may include everything from the design of the study to the selection of and interaction with participants during research processes

Question 5

participant variables

Answer 5

any individual differences between participants that may affect the DV

Question 6

situational variables

Answer 6

any features of the experimental situation (e.g. the environment) that may affect the DV

Question 7

social desirability bias

Answer 7

a tendency for responders to answer questions in such a way that presents themselves in a better light

Question 8

randomisation

Answer 8

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

Question 9

standardisation

Answer 9

using exactly the same formalised procedures and instructions for all the participants in a research study

Question 10

single blind design

Answer 10

• participants arent told the aim of the research at the beginning of the study.
• Other details may be kept from participants such as conditions of the experiment.
• Any information that might create expectations is not revealed until the end of the study to control for the confounding effects of demand characteristics

Question 11

double blind design

Answer 11

neither the participants nor the researcher who conducts the study is aware of the aims of the investigation (often conducted by a third party)