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Statistica Class Notes
Managing Data

1.0 Demonstration and explanation

Example 1.1 - Honors Thesis

Let's pretend that we are working on our honors thesis and that we want to study just "good readers", those with reading scores 60 or higher. We will open the file and then take a subset to include the students with reading scores of 60 or higher.

• File
   Open
    select File: c:\statistica\hs1.sta       
     Open

• Data
   Subset/Random Sampling...
    Variables
     click on "Select all"
      OK
       click on "Use selection condition expression"
        Cases
         click on "Specific, selected by" in the "include cases" box
          in the "Specific, selected by" box, type read >= 60
           OK
            OK

Notice that a new data set has been created with only the desired cases.  Now we will save our data.

• File
   Save as
    c:\statistica\honors\hsgoodread.sta
     Save

Example 1.1 continued - keeping variables

We want to keep just some variables, including id female read and write. 

• Vars
   Delete...
    select the variables that you want to deleted
     OK

Example 1.2 Masters Thesis

Let's suppose we are working on our masters thesis.  The data are located in a folder called c:\statistica\masters and there are two files in this folder, one for the males (hsmale.sta) and one for the females (hsfemale.sta).  We would like to combine these files.

• File
   Open
    choose c:\statistica\masters\hsmale.sta
     Open

• Statistics
   Basis Statistics/Tables
    Frequency tables
     OK
      Variables
       select female
        OK
         Summary

• single-click on the hsmale.sta data window to activate it.

• Data
   Merge
    Cases
     choose c:\statistica\masters\hsfemale.sta
      Open

• File
   Save As
    c:\statistica\masters\hsmasters.sta
     Save

Example 1.3 Dissertation

Now let's suppose that we are working on our dissertation.  The data are in a folder called c:\statistica\diss and there are two files in this folder, one with the demographic information (hsdem.sta) and one with the test scores (hstest.sta).  We would like to match merge these files based on id.  Before we can match merge these files, we need to open each file, sort it on id, and then save the sorted file.

• File
   Open
    c:\statistica\diss\hsdem.sta
     Open

• Data
   Sort...
    under "Key 1" select var and id
     OK

• File
   Save As
    c:\statistica\diss\hsdem.sta
     Save

Now that we have sorted and saved the first file (hsdem.sta), we will do the same thing for the second file (hstest.sta).

• File
   Open
    c:\statistica\diss\hstest.sta
     Open

• Data
   Sort...
    under "Key 1" select var and id
     OK

• File
   Save As
    c:\statistica\diss\hstest.sta
     Save

Finally, we will open the first file (hsdem.sta) and merge it with the second file (hstest.sta).  We will save the merged data file with the name hsdiss.sta.

• File
   Open
    c:\statistica\diss\hsdem.sta
     Open

• Data
   Merge
    Variables
     choose c:\statistica\diss\hstest.sta
      Open
       under "Mode", click on "relational"
        under "Relational merging options" type in the variable number
        of id in both files
         OK

• File
   Save As
    c:\statistica\diss\hsdiss.sta
     Save

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