Bought at the newsstand or delivered in the mail, the print edition of a magazine or journal disappears into a black hole from which only snippets of usage information escape. Relying on sample surveys or questionnaires, letters from readers, and informal comments made at meetings or dinner parties, publishers, editors, and writers get just the slightest hint of what readers look at and how long they spend with particular articles.

The situation is quite different for an online publication. Detailed, automatically maintained logs track a visitor's peregrinations from page to page. Properly analyzed and presented, those logs provide a wealth of data, from the total number of visitors to the Web site each day to the amount of time a visitor's browser remains riveted to a particularly engrossing article.

At Science News Online, daily reports provided by the WebTrends Log Analyzer have proved valuable not only for counting the number of visitors, page views, and hits each day but also for monitoring Web site activity, especially the popularity of individual articles and the existence of links from other sites that lead to sudden, topic-driven spikes in traffic. Such information helps determine which future articles will be posted on the Science News Web site, and even the placement of certain elements on the Science News Online home page.

Science News is a weekly publication based in Washington, D.C. Sixteen pages long, each issue of the print edition goes to about 200,000 subscribers and contains approximately twenty news articles. Since its inception in April 1996, Science News Online has served as a vehicle for providing additional, bibliographic material for all the articles in the print edition and for introducing nonsubscribers to the magazine. Each week, the editors select a sample of three or four articles from the print edition for posting online in their entirety. The Web site also includes four regularly updated features available only on line: Ivars Peterson's MathTrek, Food for Thought, Science Safari, and TimeLine. All posted material is archived indefinitely.

On a typical day, Science News Online currently receives about 5,000 visitors, with somewhat lower traffic on weekends. From the viewpoint of Web monitoring, however, the baseline level itself isn't as important as perturbations of that level.

A particularly dramatic example of how the Science News Online daily log report enabled us to respond in a timely fashion to strong visitor interest in a particular topic occurred on Sept. 16, 1999. That morning's report showed an unexpected, sixty-percent increase in the number of visitors to the Web site compared with the previous day. The list of "most requested pages" showed that visits to two Science News Online Web pages accounted for this abrupt boost in traffic. One was an article originally posted in September 1996 and the other provided just the references for a short article that had not been posted in full on the Web site. Both articles referred to a particle collider experiment at the Brookhaven National Laboratory in Upton, New York. We immediately responded to this evident interest by adding the full text of the missing article to our Web site.

The log report also supplied information on what brought these extra visitors to Science News Online. The list of "top referring URLs" indicated that links accompanying an online column written by Fred Moody for ABCNews.com were the source [formerly http://www.abcnews.go.com/sections/tech/FredMoody/moody990914.html]. Moody's topic had been the possibility, however small, that the Brookhaven experiment could replicate conditions in the universe just after the Big Bang, with potentially catastrophic consequences. The links to the Science News pages were apparently added to provide some scientific background information for Moody's speculations.

Interestingly, visits to these particular Science News Web pages suddenly increased again, starting on Feb. 10, 2000, after particle physicists at CERN in Switzerland announced a major new finding. Several news organizations, including ABC News, provided links to the archived Science News articles.

In numerous other cases, we have responded to unusually high interest in the online references for particular Science News articles by adding them to our online archive of full-text articles.

The Science News Online logs show that the magazine's Web site is heavily used for finding information on particular topics. The search page, in particular, gets a large number of hits each day. In recently redesigning the Web site, we responded to this pattern by making the search function operate more efficiently and placing it more prominently on each Web page.

We have also noted that our extensive year-end listing of top news stories attracts a great deal of attention, even years later. As a result, we continue to provide "Science News of the Year" from 1996 to 1999 as an online resource that is prominently featured in our archives. Similarly, we found that the previous week's table of contents, with links to full-text articles and references, is often nearly as popular as the current week's listing. We now make it easier for visitors to view the older material directly from our home page.

According to the WebTrends logs, some topics are of immediate interest to visitors, whereas others start off slowly but continue to attract attention years later. Articles on climate change, dinosaurs, unusual critter behavior, human psychology, planetary studies, and cosmology, for instance, often yield much immediate traffic. Articles on biomedical topics typically attract fewer visitors initially but can still command attention a long time after the original posting.

A 1997 news article on the virus responsible for the deadly 1918 flu epidemic, for example, continues to attract as many as four or five dozen visitors a day. A significant portion of those visits arrive via a listing in a Yahoo! directory. Another article on gastrointestinal ailments has experienced a steady stream of two dozen or more visitors nearly every day since late 1996.

The Science News Online archive now contains more than a thousand articles. Though just a few dozen articles get the bulk of visitors on any given day, a significant proportion of the total archive attracts some attention. As a result, the daily logs are huge, and we tend to focus on the top-50 requested pages. Weekly and monthly summaries help pinpoint pages that attract sustained, though relatively low-level, attention.

"Logs provide a huge amount of data that can effectively guide ongoing Web site development"

The "top referring URLs" list is particularly useful for tracking which outside Web sites provide links to Science News Online articles. Recent attention paid to an article titled "Ishi's Long Road Home," for example, was driven by a mention and link at a Texas A&M University anthropology news Web site. A posted article on potential osteoporosis drugs became a topic of interest in several investment discussion forums. Science News writers are routinely notified of such evidence of interest in their articles. They particularly appreciate finding out the many different, and sometimes surprising, ways in which particular topics attract attention. A perfume company, for example, had a link (no longer active)link to a Science News article on pheromones.

The average time that visitors spend at a given page also provides useful information. On average, visitors spend about 8 to 10 minutes at Science News Online. Interestingly, the amount of time spent looking at an individual article is roughly proportional to the article's length, suggesting that many visitors read the articles online rather than printing them out or storing them for later perusal.

In addition, data on daily usage show that international user sessions represent at least 15 percent of the total traffic. That fraction is far higher than the percentage of international print subscribers. This interest is one factor behind a recent decision at Science News to develop an enhanced, electronic edition of Science News that will be available to subscribers. Such an online edition of the full magazine would allow international subscribers to receive issues in a timely manner and for less than the extra cost of airmail postage.

As we have learned at Science News Online, a Web site's logs provide a huge amount of data, which can effectively guide ongoing Web site development. Even without collecting data via cookies or online forms, we can see the steady growth in traffic month by month. We can also glean fascinating insights into the way visitors use the Web site and the sort of information they seek.

Ivars Peterson is the mathematics/computers writer and online editor at Science News magazine (http://www.sciencenews.org/) in Washington, D.C. He writes the weekly online column Ivars Peterson's MathTrek, which is featured on several Web sites (http://www.maa.org/news/columns.html and http://www.sciencenews.org/pages/sn_weekly/math_arc.asp), and monthly articles for the children's magazine Muse (http://www.cricketmag.com/ProductDetail.asp?pid=12). Ivars is also the author of several books, including The Mathematical Tourist, Islands of Truth, Newton's Clock, Fatal Defect, and The Jungles of Randomness. Wiley has just published Math Trek: Adventures in the MathZone (http://www.maa.org/reviews/mathtrek.html), a math book he wrote with his wife, Nancy Henderson, for children ages 10 and up. He is now working on a book about mathematics and art. You may contact him by e-mail at [email protected].

Links from this article:

ABC News, http://www.abcnews.go.com

CERN announcement, http://newstate-matter.web.cern.ch/newstate-matter/

Fred Moody column [formerly http://www.abcnews.go.com/sections/tech/FredMoody/moody990914.ht ml]

Science News Online, http://www.sciencenews.org

Texas A&M University, http://www.tamu.edu/anthropology/news.html

Web Trends Log Analyzer, http://www.WebTrends.com

Yahoo! Directory Listing: http://dir.yahoo.com/Arts/Humanities/History/By_Time_Period/20th_Century/1918_Influenza_Pandemic/