Multiple Regression in SPSS - R Square; P-Value; ANOVA F; Beta (Part 1 of 3) - YouTube

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In this video, we'll take a look at how to run a multiple regression in SPSS. And
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on your screen as an example we have four variables SAT score,
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social support, gender, and college GPA.
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And in this example we're using the first three variables SAT score, social
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support, and gender,
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to predict first year college GPA. And here SAT score was taken in high school,
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social support is a measure of how much support a student felt that they received
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from others, where higher scores indicate greater support, and that was taken in
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the first year in college, and then gender, our dichotomous variable, where
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1 is male and 2 is female,
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and the variable, college GPA, was the GPA after the first year in college. And in
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regression
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what we're trying to predict in this case, college GPA, is known as our
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criterion variable.
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It's also known as the dependent variable (DV).
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And then the variables that we're using to predict the criterion variable, SAT
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score, social support, and gender,
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those are known as are predictors or predictor variables,
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and we also refer to those as independent variables (IV).
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And those once again are SAT score, social support, and gender. Now in multiple
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regression
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you always have one criterion or dependent variable, and for it to be
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multiple regression you have to have two or more predictors or independent
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variables.
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if you just had one predictor or independent variable, such as SAT score,
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then that would be simple regression. But since we have two or more, in this case
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we have three once again, we're doing multiple regression.
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OK so to run multiple regression SPSS we want to go to Analyze,
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and then Regression and then go ahead and select Linear.
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And here we want to move college GPA to our Dependent box and then we want to
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select all the predictors and move those to our Independent(s) box.
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And then go ahead and click OK. And our output opens here and the first table,
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Variables Entered/Removed,
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this confirms that we had the variables gender, SAT score, and social support as
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our predictors, and then our dependent variable, or criterion variable, was
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college GPA, so that looks good.
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OK our next two tables, Model Summary and ANOVA, these two tables, they're
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looking at whether are predictors, once again,
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SAT score, social support, and gender, when those are taken together as a set
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or as a group,
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do they predict college GPA. And the Model Summary and ANOVA table are
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getting that slightly different things, but they're very closely related.
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So let's go ahead and start with Model Summary and take a look at that.
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So for Model Summary in this video we're going to focus on R square and then in
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another video we'll talk about these measures in more detail.
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But for this general overview the most commonly reported value in the Model
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Summary table is the R square value. And R squared, if I round this to two decimal
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places and then convert it to a percentage,
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so this would round two .50 or 50%, I could interpret R squared as
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follows.
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R squared once again is equal to .50 and then taken as a set the predictors
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SAT score, social support, and gender, account for 50% of the
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variance in college GPA.
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OK so R squared is a measure of the amount of variance in the dependent
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variable
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that the independent variables or predictors account for when taken as a
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group. And that's very important,
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it doesn't measure how much a given individual predictor accounts for, but
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only when we take them all as a group, this Model Summary table says overall,
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the regression model, which is what is referred to sometimes as a model,
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these three predictors predicting college GPA,
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that overall model accounts for 50% of the variance. Which is pretty
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good in practice.
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OK next we have our ANOVA table