InfoGuides: Find Data for Analysis: Get Important Tips & Tools

Common Issues

What kind of file(s) do I have? Look at the file extension. Starting from the top, find the first row that is for any of your files.

If you have one of these...	File Type	What to do
.zip, .tar, .gz	Zip File	Unzip it, see the tab for instructions
.sav, .dta, .sas7bdat, rda, .rdata	Data formatted for a specific software	Find instructions for the software you have.
.sps, .do, .dct, .sas, .R	Setup Files	See the tab for instructions
.xls, .xlsx, .ods	Excel File	Open in Excel or any statistical software
.csv, .tsv	Delimited Text Files	Open in Excel or any statistical software
.txt, .dat	Unknown Text Files	Look at the documentation
.xml, .json	Other Structured Files	Look at the documentation

Files are compressed, or zipped, to save storage space and/or to bundle several files together. These are the most common extensions for this kind of file.

.zip Files

Windows - Instructions from Microsoft
Mac - Double-click the .zip file

Even though you can see what is in the .zip file, you must unzip the file before you can open the individual files in the archive.

.tar, .gz, or .tar.gz Files

Mac - double-click the file.
Windows - you will need to have software such as Win-Zip, PeaZip or 7-zip (instructions)

Setup Files

In some cases, you will need to download data in ASCII (text) format and use a setup file (typically .sps, .do or .sas) to get it into your software.

If using Windows, many statistical packages will not run a set-up file unless you reset the Windows Explorer to show file extensions.

SPSS: ICPSR: pdf or YouTube; Roper
Stata: ICPSR: pdf or YouTube; Roper
- You should have three files, a .do file, and .dct file and a datafile (usually .txt or .dat)
SAS: ICPSR: pdf or YouTube

Converting Files (SPSS, Stata, SAS, R)

What software do you want to use?

SPSS or SAS

Both SPSS and SAS can open from and save files to SPSS, Stata, and SAS without additional steps.

Stata

from SPSS: On Windows, you can use usespss in Stata (see tab).
from SAS: For SAS Transport files (.xpt), use import sasxport.
Alternatively, you can use Stat/Transfer or R. See tabs in this box for more info.

R

DataCamp’s This R Data Import Tutorial Is Everything You Need
ICPSR's How do I read data into R? (pdf)

Stat/Transfer

The Digital Scholarship Center (DiSC) has a software called Stat/Transfer that can convert files from one software to another.

Email datahelp@gmu.edu for assistance with accessing this software or converting your file.
Stat/Transfer is also available in the Van Metre Hall computer lab (Arlington Campus).

SPSS to Stata: Using Stata

Best option, but WINDOWS ONLY

1. Open Stata on a Windows computer

2. In the command window, submit the below syntax;

set more off net from http://radyakin.org/transfer/usespss/beta net install usespss usespss

3. Select the SPSS .sav file in the dialog box that will pop up.

4. Save the data file [in Stata format]

SPSS to Stata: Using R

1. Download the installation file from CRAN ( pdf with details )

2. Install then open R ( screenshots )

3. At the prompt (>), paste the following lines and press enter,

library(foreign) file <- file.choose() spss <- read.spss(file) data <- as.data.frame(spss) attr(data,"var.labels") <- as.vector(attr(spss,"variable.labels")) write.dta(data, sub('.sav','.dta',file))

4. Select the SPSS .sav file in the dialog box that will pop up.

5. Look for the Stata (.dta) file in the same directory.

Notes:

User Missing values are kept as is and not converted to Stata missing values.
String variables are "encoded" into labeled numeric variables.
String variables with labels do not transfer properly.

SAS to Stata: Using R

1. Download the installation file from CRAN ( pdf with details )

2. Install then open R ( screenshots )

3. At the prompt (>), paste the following lines and press enter,

install.packages("haven") library(haven) file <- file.choose() sas <- read_sas(file) write_dta(sas, sub('.sas7bdat','.dta',file))

4. Select the SAS .sas7bdat file in the dialog box that will pop up.

5. Look for the Stata (.dta) file in the same directory.