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To calculate the mean and standard deviation in SPSS, first open your dataset in the software. Then, go to the “Analyze” menu and select “Descriptive Statistics.” From there, choose “Descriptives” and select the variables you want to calculate the mean and standard deviation for. Click “Options” to make sure the mean and standard deviation are selected under the “Statistics” tab. Finally, click “Continue” and then “OK” to generate the results, which will be displayed in the output window. The mean is calculated by summing all the values and dividing by the number of cases, while the standard deviation is calculated by taking the square root of the variance.
The value of a dataset represents the average value. It gives us a good idea of where the center of a dataset is located.
The of a dataset represents how spread out the values are in a dataset. It gives us an idea of how closely the observations are clustered around the mean.
Using only these two values, we can gain a strong understanding about the distribution of values in a dataset.
The easiest way to calculate the mean and standard deviation of a dataset in SPSS is to use Analyze > Descriptive Statistics > Descriptives.
The following example shows how to do so in practice.
Example: How to Calculate Mean and Standard Deviation in SPSS
Suppose we have the following dataset in SPSS that shows the exam scores received by various students in some class:
To calculate the mean and standard deviation of exam scores, click the Analyze tab, then click Descriptive Statistics, then click Descriptives:
In the new window that appears, drag Exam_Score to the Variables panel:
Then click the Options button. In the new window that appears, make sure to check the boxes next to Mean and Std. deviation:
Then click Continue. Then click OK.
The following output will appear:
- The mean exam score is 89.67.
- The standard deviation of exam scores is 8.372.
In addition to calculating these metrics, it can be helpful to create a histogram to visualize the distribution.
To do so, click the Graphs tab, then click Histogram:
In the new window that appears, drag Exam_Score into the Variable panel:
Once you click OK, a histogram will be generated that shows the distribution of exam scores:
This histogram helps us see that although the mean exam score is 89.67, the exam scores vary quite a bit, ranging from the mid 60’s to the high 90’s.
Additional Resources
The following tutorials explain how to perform other common tasks in SPSS: