This presentation all about the regression and multiple regression equation of multiple regression and the most important thing is the research question of multiple regression with examples
3. Content
General purpose and Description
Kinds of Research Question
Limitation to Regression Analysis
Fundamental Equations for
Multiple Regressions
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4. Multiple Regression
? Multiple regression is an extension of simple regression.
? It is a study of more than two variables.
? It is used for prediction.
? It is used when we want to predict the value of a variable based on the value of
two or more other variables.
? The variable we want to predict is called the dependent variable and the variable
we are using to predict the dependent variable is called independent variables.
? The dependent variable is variously known as explained variables, predictand
and response variables.
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? While the independent variable is known as explanatory and regressor variable.
? Here we try to predict the change in Dependent variable according to change in
independent variable.
? The objective of multiple regression is to develop a prediction equation that
permits the estimation of the value of the dependent variable based on the
knowledge of multiple independent variables.
? It is used to estimate the relationship that exists, on the average between the
dependent variable and independent variable.
? It is used to determine the effect of the each independent variable on the
dependent variable, controlling the effects of all other independent variables.
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8. Example 3:
Effect of violence, stress, social support
On
internalizing behavior problems
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9. Kinds of Research Question
Research Question 1
How well do these three IVs:
? No of cigarettes / day (IV1)
? Exercise (IV2) and
? Cholesterol (IV3)
predict
? CHD (Cigarettes & coronary
heart disease) mortality (DV)?
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Cigarettes
Exercise CHD Mortality
Cholesterol
10. Research Question 2
To what extent do personality factors (IVs) predict annual income (DV)?
Extraversion
Neuroticism Income
Psychoticism
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11. Research Question 3
^Does the # of years of formal study of psychology (IV1) and the no. of
years of experience as a psychologist (IV2) predict clinical psychologists¨
effectiveness in treating mental illness (DV)? ̄
Study
Experience
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Effectiveness
12. Limitation to Regression Analysis
Multiple regression is the most powerful technique available to researchers. But
powerful techniques have high demands. So, this technique requires:
? Every variable is measured at the interval-ratio level
? Independent variable does not interact with each other
? Independent variables are uncorrelated with each other
? More difficult to implement
? Best to have a lot of data points
? It involves very lengthy and complicated procedure of calculations and analysis.
? It cannot be used in case of qualitative phenomenon.
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13. Fundamental Equation for Multiple
Regressions
? = ?0 + ?1 ?1 + ?2 ?2 + ? ? ? ? ? + ?
? = ? ? + ? ? ? ? + ? ? ? ? + ? ? ? ? ? + ?
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Dependent
Variable
Coefficients
Independent
Variable
Number of
Observations
Random
Error Term
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? Dependent Variable: The single variable being predicted by the
regression model
? Independent Variable: The independent variables used to predict the
dependent variable.
? Coefficients (β): Values, computed by the regression tool, reflecting
independent variable to dependent variable relationships.
? Random Error Term (ε): The portion of the dependent variable that isn¨t
explained by the model; the model under and over predictions.
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