How To: Interpret Webalizer Stats

Disclaimer

Clockwork collects web server logs and processes them with Webalizer as a courtesy to our clients. We don't make any claims about the relevancy of those stats for a particular use nor do we claim they are the state-of-the-art of web site analytics. The raw logs are available for download by clients for processing with WebTrends or other commercial web analytics software. We are also happy to work with clients to integrate cookie-based stats such as Google Analytics or Mint -- something easily done with the AMM. We have also on many occasions created specific logging and reporting functions based on specific client needs.

Interpreting web stats is an inexact science for two primary reasons:

1. IP addresses are shared among many users. One common example is: many companies use a firewall such that all web traffic originates from a single IP address. Large ISPs (such as AOL but including many, many others) use firewalls, proxies or otherwise re-use addresses as well. The result is -- it is easy to count unique IP addresses, it is almost impossible to count unique visitors.
2. The terms involved are not well defined. A "page view" is normally meant to mean a load of a page and all of its associated images and text. A "hit" is a single request for a single item. A "visit" is a load of several pages by one person within some amount of time. All of these definitions leave ambiguities. Page views can be skewed by robots, spammers or on-going development. Counting hits rewards sites that use many, many images in a single page. The notion of visits depends crucially on an arbitrary length of time -- if one stats package defines a session as 5 minutes and another as 15 minutes, they will produce greatly different results.

The most important things to look at for gaining knowledge from web stats are trends. If you are interested in quoting numbers, quote percentages e.g. "Home page traffic is up 400% and our hits went up 1000% when we ran that ad." If you must quote absolute numbers, quote or footnote the source of those numbers. "According to Google we have 10,000 unique visitors per day."

Basic Stats Definitions

(from http://www.mrunix.net/webalizer/webalizer_help.html) 

• Hits represent the total number of requests made to the server during the given time period (month, day, hour etc..).
• Files represent the total number of hits (requests) that actually resulted in something being sent back to the user. Not all hits will send data, such as 404-Not Found requests and requests for pages that are already in the browsers cache.
  
  Tip: By looking at the difference between hits and files, you can get a rough indication of repeat visitors, as the greater the difference between the two, the more people are requesting pages they already have cached (have viewed already).
  
  
• Sites is the number of unique IP addresses/hostnames that made requests to the server. Care should be taken when using this metric for anything other than that. Many users can appear to come from a single site, and they can also appear to come from many ip addresses so it should be used simply as a rough guage as to the number of visitors to your server.
• Visits occur when some remote site makes a request for a page on your server for the first time. As long as the same site keeps making requests within a given timeout period, they will all be considered part of the same Visit. If the site makes a request to your server, and the length of time since the last request is greater than the specified timeout period (default is 30 minutes), a new Visit is started and counted, and the sequence repeats. Since only pages will trigger a visit, remotes sites that link to graphic and other non- page URLs will not be counted in the visit totals, reducing the number of false visits.
• Pages are those URLs that would be considered the actual page being requested, and not all of the individual items that make it up (such as graphics and audio clips). Some people call this metric page views or page impressions, and defaults to any URL that has an extension of .htm, .html or .cgi.
• A KByte (KB) is 1024 bytes (1 Kilobyte). Used to show the amount of data that was transfered between the server and the remote machine, based on the data found in the server log.

Common Definitions

• A Site is a remote machine that makes requests to your server, and is based on the remote machines IP Address/Hostname.
• URL - Uniform Resource Locator. All requests made to a web server need to request something. A URL is that something, and represents an object somewhere on your server, that is accessable to the remote user, or results in an error (ie: 404 - Not found). URLs can be of any type (HTML, Audio, Graphics, etc...).
• Referrers are those URLs that lead a user to your site or caused the browser to request something from your server. The vast majority of requests are made from your own URLs, since most HTML pages contain links to other objects such as graphics files. If one of your HTML pages contains links to 10 graphic images, then each request for the HTML page will produce 10 more hits with the referrer specified as the URL of your own HTML page.
• Search Strings are obtained from examining the referrer string and looking for known patterns from various search engines. The search engines and the patterns to look for can be specified by the user within a configuration file. The default will catch most of the major ones.
  
  Note: Only available if that information is contained in the server logs.
  
  
• User Agents are a fancy name for browsers. Netscape, Opera, Konqueror, etc.. are all User Agents, and each reports itself in a unique way to your server. Keep in mind however, that many browsers allow the user to change it's reported name, so you might see some obvious fake names in the listing.
  
  Note: Only available if that information is contained in the server logs.
  
  
• Entry/Exit pages are those pages that were the first requested in a visit (Entry), and the last requested (Exit). These pages are calculated using the Visits logic above. When a visit is first triggered, the requested page is counted as an Entry page, and whatever the last requested URL was, is counted as an Exit page.
  
  
• Countries are determined based on the top level domain of the requesting site. This is somewhat questionable however, as there is no longer strong enforcement of domains as there was in the past. A .COM domain may reside in the US, or somewhere else. An .IL domain may actually be in Isreal, however it may also be located in the US or elsewhere. The most common domains seen are .COM (US Commercial), .NET (Network), .ORG (Non-profit Organization) and .EDU (Educational). A large percentage may also be shown as Unresolved/Unknown, as a fairly large percentage of dialup and other customer access points do not resolve to a name and are left as an IP address.
  
  
• Response Codes are defined as part of the HTTP/1.1 protocol (RFC 2068; See Chapter 10). These codes are generated by the web server and indicate the completion status of each request made to it.