Descriptives
This feature requires the Statistics Base option.
The Descriptives procedure displays univariate summary statistics for several variables in a single table and calculates standardized values (z scores). Variables can be ordered by the size of their means (in ascending or descending order), alphabetically, or by the order in which you select the variables (the default).
When z scores are saved, they are added to the data in the Data Editor and are available for charts, data listings, and analyses. When variables are recorded in different units (for example, gross domestic product per capita and percentage literate), a z-score transformation places variables on a common scale for easier visual comparison.
Example. If each case in your data contains the daily sales totals for each member of the sales staff (for example, one entry for Bob, one entry for Kim, and one entry for Brian) collected each day for several months, the Descriptives procedure can compute the average daily sales for each staff member and can order the results from highest average sales to lowest average sales.
Statistics. Sample size, mean, minimum, maximum, standard deviation, variance, range, sum, standard error of the mean, and kurtosis and skewness with their standard errors.
Descriptives Data Considerations
Data. Use numeric variables after you have screened them graphically for recording errors, outliers, and distributional anomalies. The Descriptives procedure is very efficient for large files (thousands of cases).
Assumptions. Most of the available statistics (including z scores) are based on normal theory and are appropriate for quantitative variables (interval- or ratio-level measurements) with symmetric distributions. Avoid variables with unordered categories or skewed distributions. The distribution of z scores has the same shape as that of the original data; therefore, calculating z scores is not a remedy for problem data.
To Obtain Descriptive Statistics
- From the menus choose:
This feature requires the Statistics Base option.
- Select one or more variables.
Optionally, you can:
- Select Save standardized values as variables to save z scores as new variables.
- Click Options for optional statistics and display order.
This procedure pastes DESCRIPTIVES command syntax.