How To Compare Two Data Sets In Spss

What are the differences in the split file options?

The Compare and Organize options produce numerically identical results when the same grouping variable(south) are applied. This is truthful regardless of what statistical analysis is used. The difference betwixt the two options is how the numeric results are presented.

• If Compare groups is used, then all of the results will be shown in a unmarried table. The table will have sections showing the results for each grouping.
• If Organize output by groups is used, then each groups' results will be put into a separate table.

The choice of which splitting method to use is entirely well-nigh what format the user wants their results in. Practise y'all desire a single table with all results, or separate tables for each group's results? A good dominion of thumb is to choose Compare Groups if you want to exist able to directly compare the results of your groups, and to cull Organize Output past Groups if the information is from divide trials or samples (such every bit cohorts from different years).

Trouble Statement

Suppose that we want to go a summary of the differences in peak between males and females in the sample data. Let's couple the Split File procedure with the Descriptives procedure to get summary statistics for the 2 groups. We'll utilize both Split File methods so that nosotros can compare what their outputs look like.

Splitting using Compare Groups

If you choose to dissever your data using the Compare groups option and then run a statistical analysis in SPSS, your output will exist displayed in a single table that organizes the results co-ordinate to the group variable(s) you specified.

Running the Procedure

To split the information in a manner that will facilitate group comparisons:

1. Click Data > Split File.
2. Select the selection Compare groups.
3. Double-click the variable Gender to motion it to the Groups Based on field.
4. When yous are finished, clickOK.

Afterwards splitting the file, the merely change you volition see in the Information View is that data will be sorted in ascending order by the grouping variable(due south) you selected.

Now allow'due south view the same descriptive statistics for the variable Height with respect to Gender. Select Analyze > Descriptive Statistics > Descriptives. Double click on the Height variable, and so click OK.

Syntax

            SORT CASES  Past Gender.  SPLIT FILE LAYERED Past Gender.  DESCRIPTIVES VARIABLES=Elevation   /STATISTICS=MEAN STDDEV MIN MAX.          

Output

This tabular array gives us a breakdown of how many observations were in each group (Northward), and the minimum, maximum, average, and standard deviation of each group. The '.' group contains cases with missing gender values and nonmissing height values. At a glance, we can quickly accept annotation that in this sample:

• The elevation of the tallest male was greater than the meridian of the tallest female.
• The male heights tended to have a slightly larger standard deviation (spread) than the female person heights.
• On boilerplate, the males were taller than the females.
• The individuals with missing values for gender had a much smaller range of heights than did the males or females.

Note: This combination of Dissever File: Compare Groups with Descriptives is very like to what you lot would get with the Compare Means procedure. The major difference is that Split File includes the missing values in the grouping/splitting variable, whereas Compare Ways excludes missing values in the grouping variable.

Splitting using Organize Output by Groups

If yous choose to split up your data using the Organize output by groups pick and so run a statistical analysis in SPSS, your output volition be broken into separate tables for each category of the grouping variable(due south) specified.

Running the Procedure

To split the data in a way that separates the output for each group:

1. Click Data > Separate File.
2. Select the selection Organize output by groups.
3. Double-click the variable Gender to move it to the Groups Based on field.
4. When you are finished, clickOK.

Later on splitting the file, the only modify you lot volition see in the Data View is that information will exist sorted in ascending club by the group variable(s) you selected.

Now nosotros volition re-run the same descriptive statistics process that nosotros ran before. You lot tin go through the menu system once more (Clarify > Descriptive Statistics > Descriptives), or you can click on the Recall recently used dialogs icon, which will bring up a listing of recently used procedures:

Syntax

            SORT CASES  Past Gender.  SPLIT FILE Split BY Gender.  DESCRIPTIVES VARIABLES=Height   /STATISTICS=Mean STDDEV MIN MAX.          

Output

After re-running the descriptive statistics, we come across that the output is broken into iii sections based on values of the Gender variable. The get-go section ("Gender = .") reports the minimum, maximum, boilerplate, and standard deviation of Acme for the students who had missing values for Gender. The 2d section reports those same statistics for the male students; the third section reports the statistics for the females.

Source: https://libguides.library.kent.edu/SPSS/SplitData

Share this post