Review Descriptive Statistics - Quick Tab

Select the Quick tab of the Review Descriptive Statistics dialog to access options to quickly review the most common descriptive statistics. Additional options are available on the Advanced tab and the Matrix tab.

Means & standard deviation

Click the Means & standard deviations button to display a spreadsheet with means and standard deviations. The mean of the sample is an unbiased estimate of the population mean. By default the standard deviation is computed as the square root of the sum of squared deviations about the mean (SS) divided by N - 1 (an unbiased estimate of sigma2). The resulting statistic is an estimate of the population sigma (this statistic can then be used to draw inferences about the population from which the sample was drawn). You can use the SD = Sums of Squares/N check box (see Review Descriptive Statistics - Advanced tab) to compute the standard deviation as the SS divided by N. This resultant statistic is a description of the standard deviation in this sample (no inferences should be drawn from this statistic, about the population that the sample came from).

A particularly useful Graph of Input Data for this spreadsheet is a histogram (frequency distribution) of the chosen variable, with the normal distribution superimposed. This plot can be very useful as a quick check of whether the assumption of normality has been violated by the respective variable.

Correlations

Click the Correlations button to display a correlation matrix spreadsheet of the selected Variables. A particularly useful Graph of Input Data for this spreadsheet is a scatterplot of the respective two variables. The plot will indicate the regression line as well as the 95% confidence limits for the regression line.

Pairwise N

Click the Pairwise N button to display a spreadsheet with the number of valid cases for each pair of variables in the correlation matrix. This option is available only if a Raw Data input file and Pairwise deletion of missing data was selected on the Multiple Linear Regression Startup Panel - Advanced tab; and when this dialog is first displayed after the data have been read (i.e., only if the Review descriptive statistics, correlation matrix check box was selected from the Multiple Linear Regression Startup Panel - Advanced tab as well).