To avoid bias, the following control procedures are often used. Control Procedures Blind Control is where subjects are uninformed about the purpose of the research study or some key part of it. Double blind is where both researchers and subjects are uninformed about the nature of the independent variable being administered to the subjects. Confounding variables are changeable factors that could be confused with the independent variable and this distorts the results. Research Methods Psychological Measurement Research Design Correlation Experimentation Psychological Measurement Self-report measures involve answers, either written or spoken, to questions posed by the researcher.
Behavioral measures are ways to study overt actions and observable and recordable reactions.
Physiological measures involve the use of special instruments to show biological reactions to stimuli, such as brain activity in some measurable form. Research Design Correlation Correlation methods are used to determine to what extent two variables, traits, or attributes are related. A correlation coefficient is a statistical measure that reflects the precise degree of correlation that exists between two variables. Correlation does not imply causation. Randomization involves assigning subjects in such a way that each subject had an equal chance of ending up in any of the conditions, experimental or control.