PDF - Appropriate Uses
What is a PDF?
PDF (Portable Document Format) files are a digital representation of a printed document, and are useful for presenting certain types of information such as long publications. However, overuse of PDFs make web sites less friendly to visitors because:
- Loading a PDF often causes the browser to "hang" while the PDF reader opens.
- Going from a page to a PDF is not a seamless experience, since it removes the site navigation cues, and a PDF viewer behaves differently than a web browser.
- Clicking on a link to open a PDF can surprise a user who expects links to lead to pages. This violates the "Principle of Least Surprise."
- Downloading a PDF often takes longer than viewing a web page because of the larger file size, which is a large problem for those using a dialup connection.
- Using bookmarks or a table of contents within a PDF requires extra manual effort on the part of the author. This type of navigation is easily done with the AgSci content management system (CMS).
- PDFs are generally not accessible to screen reader users, which is not compliant with the Penn State policy AD-69: Accessibility Of Penn State Web Pages.
- PDFs are more difficult to read on mobile devices than a corresponding page in the Plone CMS.
And, PDFs create problems for content owners:
- Maintaining a PDF involves more steps than creating the equivalent content in Plone.
- Visits from search engines to PDFs are not tracked in Google Analytics, which deprive you of valuable data on your site.
- Penn State and college branding standards are occasionally updated. The web team handles these for the website, but the content owner is responsible for ensuring that PDFs are compliant.
When is it appropriate to use a PDF?
Appropriate uses of a PDF include:
- The material being presented is meant solely for print rather than being read in a browser or on a mobile device. Examples include manuals and publications.
- The document is very long and cannot be easily made web-friendly.
- The document is a form intended to be printed and faxed/mailed.
When shouldn't I use a PDF?
In most cases, a web page should be used rather than a PDF, except as stated in the above examples. Specific examples in which PDFs have been used in the past when a page is more appropriate are:
- The author maintains a Word document on their computer, prints the document to PDF, and uploads to the web site. This is more work for the author, and less friendly for the visitor. Site content should be maintained on the site, not on the author's computer.
- The site owner receives a graphical flyer in PDF form for an event, and wants to feature that event on their site. Creating a Plone event (or events) with the information allows that event to be integrated into the site, and presents a consistent experience to the visitor.
- The audience wants to print the information in addition to reading it on the web. The pages in the AgSci CMS are printer friendly without any additional work on the author's part. Although the layout can't be as tightly controlled as a PDF, it is a good compromise in web friendliness, print readability and effort on the part of the author.
PDF Version of Pages
Historically, some sites have had PDF versions of pages available for download. Our recommendation is to provide only the web version, and not duplicate content in a separate PDF version. Having only a web version eliminates:
- multiple places to update content, of which the web is the easiest
- duplication of content between the PDF and web, potentially affecting search engine results to a small degree
- updates to PDFs if/when branding standards are updated
We reviewed the traffic for one site where the "PDF version" was widely used, and found:
- The ratio of pageviews to PDF downloads for pages with a PDF version was 27:1. In other words, for every time someone downloaded the PDF, 27 people viewed the web version.
- Only 15% of the traffic for the PDF version came from search engines, as opposed to 65% across all AgSci sites. This indicates that the PDF version is less findable by search engines.
The "printed from the web" pages, while not as polished as a dedicated PDF version, are clean, usable, and branded. The web version is much easier to maintain than the PDF version, and receives far more traffic than the PDF version.
PDF Brochures and Flyers
The information in PDF versions of brochures and flyers should be converted to web-friendly content instead of posting the PDF on the site. This ensures that the content is easier to read, easier to update, and more findable by search engines.
In particular, the tri-fold brochure format is unsuitable for presentation on the web because it appears as:
|Panel 2||Panel 6
|Panel 3||Panel 4
This forces users to perform mental origami to reassemble the panels into their intended order.
The exception would be where the brochure or flyer contains a registration form which must be printed, filled out, and returned.
Naming Your PDF File
PDFs should be named in accordance with the AgSci URL Standard. For example, 'the-file-name.pdf' would be a valid file name. 'The File Name (version 2).pdf' would not.
PDF Title and Description
Users need to be able to find your PDF when searching the web. You can help them by providing an appropriate Title and Description in the CMS. This will also help you when you need to locate the pdf for editing/linking purposes in the future.
It is a good idea to make the Title in the CMS match as closely as possible the actual title of your PDF (for example if your PDF is titled "Graduate Student Handbook: Spring Semester 2009," give it that same title in the CMS, not "blue handbook-latest committee updates" or something similarly vague). Note that this is different than the file name of the PDF.
Likewise, the Description should be a summary of the PDF's actual content rather than "handbook updated after March 1 committee meeting" or the like.
If the Title and Description contain terms that users will likely type into a search engine if they are looking for this information, so much the better.