To understand how variables are used and discussed in psychological researches, you need to understand several distinctions that are made among the type of variables. The descriptions of different types of variables are given below:
• Stimulus, Organism and Response (S-O-R) Variables Psychologists are interested in studying the behaviour or causes of behaviour as variables. Many psychologists have adopted a theoretical viewpoint or model called the S-O-R model to explain all behaviour. The symbols S, O, and R represent different categories of variables. S is the symbol of stimuli, and the category may be referred to in general as stimulus variables. A stimulus variable is some form of energy in the environment, such as light, to which the organism is sensitive. O is the symbol for organism variables , that is the changeable physiological and psychological characteristics of the organisms being observed. Examples of such variables are anxiety level, age and heart rate etc. Finally, R is the symbol for response and, in general, response variables, which refer to some behaviour or action of the organism like pressing a lever, and reaction to any stimulus, are the examples of response variables. You can understand an application of S-O-R model through the following example. Suppose that an experiment is conducted in which a rat is placed on a metal grid floor, the grid is electrified, and the length of time it takes the rat to jump from the grid to a platform is measured. Using the S-O-R model, the electrical shock would be called a stimulus variable. The intensity of shock would be the value of the variable. The particular state of the organisms would be measured by the organismic variables. For example, the skin resistance of the rat at the time of shock would be an organismic variables. A response variable would be the latency (i.e. the elapsed time between the onsets of the shock and when the rat reaches the platform).
• Independent and Dependent Variables An independent variable or stimulus variable (as Underwood calls it) is a factor manipulated or selected by the experimenter in his/her attempt to ascertain its relationship to an observed phenomenon.
A dependent variable is the factor that appears, disappears, or varies as the experimenter introduces, removes or varies the independent variable (Townsend,1953). The dependent variable is a measure of the behaviour of the subject. The dependent variable is the response that the person or animal makes. This response is generally measured using at least one of the several different dimensions (Alberto & Troutman, 2006). The dimensions are – (a) frequency – number of times that a particular behaviour occurs, ( b) duration – the amount of time that a behaviour lasts. (c) latency –the amount of time between and when the behaviour is actually performed (d) force – the intensity or strength of a behaviour.
• Extraneous and Confounded Variables Any and all other variables that may ‘mask’ the relationship between independent variable and dependent variable are known as extraneous variables. Extraneous variables may directly affect the dependent variable or may combine with the independent variable to produce an affect. Therefore, extraneous variables must be controlled so that the experimenter can determine whether the dependent variable changes in relation to variation in the independent variable. Confounding variable is one that varies with the independent variable. While doing a study if we are not careful then two variables may get combined so that the effect of one cannot be separated from the effect of other. This is known as confounding. For instance, if you conducted a study of the effect of television viewing on perception of violence and the experimental group contained only adolescents, whereas the control group only adults, the age of participants would be confounded with the independent variable under study. Confounding makes the conclusions of the study doubtful. It is therefore, necessary that effort should be made to unconfound the variables.
• Active and Attribute Variables Any variable that is manipulated is called active variable. Examples of active variables are reward, punishment, methods of teaching, creating anxiety through instructions and so on. Attribute variable is that variable which is not manipulated but measured by the experimenter. Variables that are the human characteristics like intelligence, Aptitudes, sex, socio economic status, education, field dependence and need for achievement are the example of attribute variables. The word ‘attribute’ is more accurate enough when used within animated objects or references. Organisations, institutions, groups, population and geographical areas have attributes. Organisations are variably productive; groups differ in cohesiveness; geographical areas vary widely in resources.
• Quantitative and Categorical Variables Quantitative variables is one that varies in amount whereas categorical variables varies in kind. Speed of response, intensity of sound, level of Illumination, intelligence etc. are the example of quantitative variables and gender, race, religion are the example of categorical variables. Precise and accurate measurement are possible with the quantitative variables because they can be easily ordered in terms of increasing and decreasing magnitude. Categorical variables can be of three types: Constant, dichotomous and polytomous. When a variable can have only one value or category, for example taxi, tree and water, it is known as a constant variables. When a variable can have only two categories as in yes/no, good/bad and rich/poor, it is known as dichotomous variables. When variables can be divided into more than two categories, for example: religion (Christian, Muslim, Hindu); political parties (Labour or, Liberal, Democrat); and attitudes (strongly favorable, favorable, uncertain, unfavorable, strongly unfavorable), it is called a polytomous variable.
To understand how variables are used and discussed in psychological researches, you need to understand several distinctions that are made among the type of variables. The descriptions of different types of variables are given below:
• Stimulus, Organism and Response (S-O-R) Variables Psychologists are interested in studying the behaviour or causes of behaviour as variables. Many psychologists have adopted a theoretical viewpoint or model called the S-O-R model to explain all behaviour. The symbols S, O, and R represent different categories of variables. S is the symbol of stimuli, and the category may be referred to in general as stimulus variables. A stimulus variable is some form of energy in the environment, such as light, to which the organism is sensitive. O is the symbol for organism variables , that is the changeable physiological and psychological characteristics of the organisms being observed. Examples of such variables are anxiety level, age and heart rate etc. Finally, R is the symbol for response and, in general, response variables, which refer to some behaviour or action of the organism like pressing a lever, and reaction to any stimulus, are the examples of response variables. You can understand an application of S-O-R model through the following example. Suppose that an experiment is conducted in which a rat is placed on a metal grid floor, the grid is electrified, and the length of time it takes the rat to jump from the grid to a platform is measured. Using the S-O-R model, the electrical shock would be called a stimulus variable. The intensity of shock would be the value of the variable. The particular state of the organisms would be measured by the organismic variables. For example, the skin resistance of the rat at the time of shock would be an organismic variables. A response variable would be the latency (i.e. the elapsed time between the onsets of the shock and when the rat reaches the platform).
• Independent and Dependent Variables An independent variable or stimulus variable (as Underwood calls it) is a factor manipulated or selected by the experimenter in his/her attempt to ascertain its relationship to an observed phenomenon.
A dependent variable is the factor that appears, disappears, or varies as the experimenter introduces, removes or varies the independent variable (Townsend,1953). The dependent variable is a measure of the behaviour of the subject. The dependent variable is the response that the person or animal makes. This response is generally measured using at least one of the several different dimensions (Alberto & Troutman, 2006). The dimensions are – (a) frequency – number of times that a particular behaviour occurs, ( b) duration – the amount of time that a behaviour lasts. (c) latency –the amount of time between and when the behaviour is actually performed (d) force – the intensity or strength of a behaviour.
• Extraneous and Confounded Variables Any and all other variables that may ‘mask’ the relationship between independent variable and dependent variable are known as extraneous variables. Extraneous variables may directly affect the dependent variable or may combine with the independent variable to produce an affect. Therefore, extraneous variables must be controlled so that the experimenter can determine whether the dependent variable changes in relation to variation in the independent variable. Confounding variable is one that varies with the independent variable. While doing a study if we are not careful then two variables may get combined so that the effect of one cannot be separated from the effect of other. This is known as confounding. For instance, if you conducted a study of the effect of television viewing on perception of violence and the experimental group contained only adolescents, whereas the control group only adults, the age of participants would be confounded with the independent variable under study. Confounding makes the conclusions of the study doubtful. It is therefore, necessary that effort should be made to unconfound the variables.
• Active and Attribute Variables Any variable that is manipulated is called active variable. Examples of active variables are reward, punishment, methods of teaching, creating anxiety through instructions and so on. Attribute variable is that variable which is not manipulated but measured by the experimenter. Variables that are the human characteristics like intelligence, Aptitudes, sex, socio economic status, education, field dependence and need for achievement are the example of attribute variables. The word ‘attribute’ is more accurate enough when used within animated objects or references. Organisations, institutions, groups, population and geographical areas have attributes. Organisations are variably productive; groups differ in cohesiveness; geographical areas vary widely in resources.
• Quantitative and Categorical Variables Quantitative variables is one that varies in amount whereas categorical variables varies in kind. Speed of response, intensity of sound, level of Illumination, intelligence etc. are the example of quantitative variables and gender, race, religion are the example of categorical variables. Precise and accurate measurement are possible with the quantitative variables because they can be easily ordered in terms of increasing and decreasing magnitude. Categorical variables can be of three types: Constant, dichotomous and polytomous. When a variable can have only one value or category, for example taxi, tree and water, it is known as a constant variables. When a variable can have only two categories as in yes/no, good/bad and rich/poor, it is known as dichotomous variables. When variables can be divided into more than two categories, for example: religion (Christian, Muslim, Hindu); political parties (Labour or, Liberal, Democrat); and attitudes (strongly favorable, favorable, uncertain, unfavorable, strongly unfavorable), it is called a polytomous variable.
From MPC-005 (Research Methods) – IGNOU