The other 57% of the variance is therefore caused by other factors, such as measurements errors. So, for my example, I can say that 43% of the variance in weight can be accounted for by the height measures.
Researchers often multiple this value by 100 to get a percentage value. The R square value tells you how much variance the dependent variable can be accounted for by the values of the independent variable.
To get this value, you simple square the multiple R value. You may sometimes see the R square being referred to as the coefficient of determination. If you’re interested to learn more about correlation, then I suggest you refer to the What is Pearson Correlation post. Briefly, it is a value that tells you how strong the linear relationship is.Ī value of 0.65 in this case indicates a fairly strong linear correlation between height and weight measures. This is the absolute value of the correlation coefficient between the two variables of interest. In the first table called Summary Output, there are some regression statistics from the test. I’ll now break down the output and go through each in more detail. Interpretation of the linear regression resultsĭepending on the options selected in the set-up window, you will have quite a lot of information in the results sheet. Line Fit Plots – will create another scatter graph where the Y and X variables are plotted, but it will also add the predicted Y values onto the graphįinally, the Normal Probability Plots option plots another scatter plot, which is used to determine whether the Y variable data fits a normal distribution.Residual Plots – will create a scatter graph where the residuals are plotted on the Y axis and the X variable is plotted on the X axis.Standardized Residuals – will return the standardized residuals these values can be useful when identifying potential outliers.Residuals – will return the list of predicted dependent values, based on the regression line, as well as the residual values for each point.The final set of options concerns the residuals in the analysis. New Workbook – lets you save the results in an entirely separate workbookįor my example, I’m going to select the second option and have the results placed in a new worksheet.New Worksheet Ply – lets you place the results in a new worksheet.Output Range – you can highlight where you want the results to be placed in that worksheet.Output optionsįor the Output Options, you can specify where you want the regression results to be placed. However, if you want to use a different confidence level than 95%, then you need to select this option and enter the desired value here. By default, the results will return the 95% confidence intervals without having to change any options. It is also possible to specify the confidence level for the test. Generally, for linear regression, this option is not selected, so I will leave it unchecked for this example. Doing so would mean there is no Y intercept in the model. The next option called Constant is Zero is used if you want the regression line to start at 0, otherwise known as the origin. If you didn’t have any labels when you selected your data, then you should not tick this option. If you have highlighted the labels of the columns when selecting the data, then tick the Labels options.
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