How to download SPSS files from IDLS

IDLS - Internet Data Library Service

IDLS is a data extraction service developed and maintained by the Social Science Computing Laboratory at the University of Western Ontario. It provides access to most -- but not all -- of the data available through the DLI. The advantage of using an extraction service such as IDLS is that the researcher can readily identify, select and download variables which can then be custom-tabulated through SPSS. This guide provides a brief introduction to:

Downloading data from the IDLS site
Uncompressing it
Importing it to SPSS

It requires the use of two software packages, WinZip (or other data compression utility) and SPSS.

Accessing IDLS

From the Memorial University Libraries' homepage (http://www.library.mun.ca):

Select Internet Resources, then Canadian Statistical Sites.
Scroll down to Internet Data Library System (IDLS). If you are off campus, you must use the off campus login before accessing IDLS
Select Internet Data Library System (IDLS)

Step 1 - View, select and download variables from a file

Select the data set you want by browsing by name or category, or by keyword searching. NOTE: only the data with the file type raw data can be imported into SPSS
The list of variables labels and titles will appear and can be selected individually. To get a description of a variable, click on the variable name.
Select the variables you wish to download and click Select values for selected variables
At this point you can choose to specific values for each variable (for example, only cases that have Newfoundland in the PROVINCE variable), or choose all values (this is the default)
Click on Submit
Enter your e-mail address and select SPSS code file.
Click on the URL which appears to begin downloading the data to your machine.
You will also receive an e-mail message containing the URL for your data set and a password for extracting the data.

Step 2 - Download the zipped file to your hard drive and uncompress it

Save the file to the temp directory on your hard drive
Double click on the file to open WinZip. You should see three files: the data (.dat), the SPSS syntax file (.sps) and the codebook (.html).
Select all three files (Click on Actions - Select All)
Click on Actions - Extract�
Select the folder in which you wish to save the files (note: it is advisable to create a separate directory for each dataset you download, i.e., c:\data\socialsurvey03)
Enter your password (you must retrieve your password from the email sent by IDLS)
Close the WinZip window.

NOTE: if you are using a different compression utility, use that program's help feature to determine how to unzip the files.

Step 3 - Import the data set into SPSS

The three files that should appear unzipped in the directory are:
Data file (.dat): Contains the raw data for the variables that were extracted.
SPSS file (.sps): Contains the SPSS command file.
HTML file (.html): Contains the customized codebook for the subset of variables extracted.

Click on the SPSS icon (.sps file) to open the command file. SPSS should open automatically.
On the line that begins "data list�" indicate the location of the data file. If your data is in the directory c:\data\socialsurvey03, you must change the line that reads file='?:\?\ftp#####.dat' to file='c:\data\socialsurvey03\ftp#####.dat
Click on Run/All.

Unless an error was made in specifying the location and name of the data file, the data should have been read. The SPSS Viewer will display the list of variables that have been input and the SPSS Data Editor will show the active file.

NOTE: IDLS also contains syntax files for SAS and STATA. Follow the instructions with those programs for step 3.

July 15, 2008
Gillian Byrne