American Library Association
The purpose of this web page is to provide explanations of the most heavily used alternative formats, along with information about the software programs necessary for viewing documents in these formats. Many government agencies, such as the Census Bureau, Bureau of Labor Statistics, Bureau of Justice Statistics, National Center for Education Statistics, and the National Center for Health Statistics, provide explanatory pages for accessing information in alternative formats. If while searching government web sites, you come across an alternative viewing format that you feel needs further explanation, please contact Stephanie Atkins. An explanation of the software program requirements for the format will be added to this page. Thank you.
PDF files are compact, cross platform files that can be viewed with Acrobat Reader software. This software is available free of charge. You must have a copy of the Adobe Acrobat Reader Software installed on your computer to view a PDF file. (You may already have this program on your computer.) The Adobe Acrobat Product Information page provides explicit downloading and installation instructions, including a three-step process to register, select the appropriate software version, and configure your web browser.
Some files may be difficult to read from the screen. However, the Acrobat Reader's navigation and zoom features enable closer review of text and images within a PDF file. The Acrobat Reader also allows you to print these files exactly as they were originally published. It is possible to download PDF files which can then later be opened by you with your Acrobat Reader. Specific instructions are not provided for you on this page because they will vary slightly depending on your Internet browser configuration. It is recommended that you check with your library computer technician for specific instructions.
To successfully decompress a file, you must first save (download) the file to your computer. Clicking on a link usually initiates the downloading process. Second, unzip the file using a decompression program. Third, view the unzipped file or files using the appropriate software for the file format. Common file formats of unzipped files include .txt (ASCII format which can be read by word processing programs such as WordPad, WordPerfect, or Word), .wk1, .dat, or .xls (spreadsheets which can be read by programs such as Lotus or Excel), and .zip (files that can be open and read within your zip program).
In order to decompress ZIP files, you must have a file utility that can be used to extract the individual files from the compressed binary file - - otherwise known as "unzipping" the files. Several zipping programs, including freeware, shareware, and commercial products, are available. You may have an unzip program already loaded on your computer. One of the most popular shareware programs is PKZIP which runs on MS-DOS, OS/2, Windows 3.1, Windows 95, Windows NT 3.441+, UNIX, OpenVMS VAX, and Alpha environments. Check out the PKWARE downloading page for instructions on how to obtain PKZIP/UNZIP. Another popular program is WINZIP which runs on Windows 3.1, Windows 95, and Windows NT. Pricing for WINZIP varies depending on whether you are purchasing a single copy or a site license. ZipIt, a shareware program for $15.00, is a popular unzipping utility for Macintosh users.
Examples of ZIP files:
The Bureau of the Census often uses compressed zip files. One example, State Projection Components of Change:1995 to 2025, provides compressed data for each state. You might want to use this page to practice downloading a zip file, unzipping the file, and then reading the files. These files are text files (.txt) which can be read with a word processing program such as WordPad, Word, or WordPerfect. Alternatively, Historical Data from International Price Indexes contains zip files for downloading that, after unzipping, are in spreadsheet formats (.xls), which can be read with a spreadsheet program such as Lotus or Excel.
AlternaTIFF is a free Netscape-style browser plug-in that displays most of the common types of TIFF image files. It is compatible with Netscape Communicator 3.0 and higher and Internet Explorer 3.0 and higher. It is a 32-bit Windows program, and requires Windows 95, Windows 98, or Windows NT 4.0, and a 32-bit browser.
An Apple Macintosh® plug-in which works with images from the Patent
and Trade Office is Acordex Imaging Systems Accel
ViewTIFF, which offers a free 14-day demonstration. It works in both IE 4+ and Netscape 4+.
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maintained by Stephanie Atkins (firstname.lastname@example.org); last updated February 14, 2000.
Originally compiled by Ann Roselle.