Data Services: Getting & Using Data On SSDS Disk Space

Direct Data Access from your Leland SUNet Account  |  Transferrring Data to your PC  |  Now That You've Got Your Data, What Next?

Direct Data Access from your Leland SUNet Account

SSDS staff loads the data from your ICPSR or Roper requests on our disk space on the Leland Systemsand sends an email notice with directions to the data. ITSS (Information Technology Systems and Services) offers excellent documents on UNIX and PICO on their UNIX Reference Documentation page. For assistance using statistical software on the Leland Systems, check out our SSDS"Getting Started" guides and documents.

Transferrring the Data to your PC

Options for getting data on SSDS disk space on the Leland Systems and transferring it to your personal computer include: (1) using a Web browser; (2) an FTP program such as SecureFX for Windows or MacSFTP for the Macintosh; and (3) MacLeland or PC-Leland/PC-AFS to mount Stanford's AFS disk space to your desktop. This option is recommended if you have a fast connection to the Stanford network. Download the FTP and AFS programs from Essential Software for Mac and PC. Details about transferring files using the Web and secure FTP and AFS mounting are available atTransferring Files at Stanford .

Once your program is installed, use the full remote site pathname that you received via email (e.g. /afs/ir/data/ssds/data14/icpsr6010) and navigate (change directory) to that directory. Then select and move files from the remote site to a directory on your personal computer.

Now That You've Got Your Data, What Next?

The data codebook is the key that describes the data, its layout, definition, and other important information to correctly use it. For example, the codebook might specify that the 'sex' variable has values 1, 2, and 9 located in column 13 in the datafile with labels 'male', 'female', and 'missing'. This data dictionary information is used to import the raw (text) datafile into a statistical application for further analysis.

In the past, the codebooks were only available in printed form. Copies of printed codebooks in the Stanford University Libraries are cataloged inSocrates. If you are using an ICPSR dataset, then a quick way to see if the library owns a printed copy of its codebook is to do a 'Keyword' search with 'ICPSR' and the ICPSR study number (e.g., 'ICPSR 7937'). The call number and location of any printed copies of the codebook will be listed in the 'Long' record for that dataset title.

Today, most codebooks are distributed in electronic format as text or pdf files. For ICPSR datasets, codebook filenames usually begin with 'cb'. Codebooks that are in text or ASCII format can be read using simple text readers, such as Notepad or WordPad (Windows) or SimpleText (Macintosh). PDF codebook files must be read using Adobe Acrobat Reader, available at the Essential Software for Mac and PCWeb site.

In addition to the codebook and raw (ASCII or text) data files, some datasets will come with SPSS or SAS file definition (syntax) code, which can be modified and run in SPSS or SAS, respectively, to load the raw data file into the appropriate statistical package. Some datasets come with the data already formatted for a statistical package (e.g., SPSS portable or SAS transport files); these files can be directly imported into their corresponding statistical package. Recently, a few datasets have come with Stata "do" and dictionary files, which can be used to input the raw data into Stata. Finally, some older ICPSR studies come with OSIRIS data and dictionary files (an old IBM mainframe statistical package). OSIRIS files from ICPSR can be converted to other statistical packages using Stat/Transfer. Contact our software consultantsfor help with Stat/Transfer or any of these statistical packages.