If you're going to get the most out of Web analytics or Web measurement, then you should know some of the more commonly used terms and what they mean. Understanding these terms in Web analytics will insure that you know what you're measuring and what information you don't have.
Hits is probably one of the most used terms in Web analytics. But unfortunately, it's also one of the most incorrectly used terms in Web analytics. According to wikipedia, a hit in Web analytics is:
"any request for a file from a Web server"
This means that every request that is made to a Web server can be considered a hit.
- Every time an image is downloaded for display on a Web page is a hit. For example, a simple Web page with four images would result in five hits to the server.
When one of your readers views your page, there can be hundreds of hits to your server. An average About article like this one generates more than 30 hits to the server.
Hits are not a useful or reliable form of Web analytics in a business context. They don't really tell you anything useful. They are only really useful if you're a Web server administrator and you want to find out why a page is slow to load.
Don't use the term hits unless you want people to know you don't know much about Web analytics or Web measurement.
Pageviews or Page Views
Pageviews are the successful loading of a dcoument from a Web server by a Web site visitor. Pageviews generally do not include:
- error pages
- views by robots
Pageviews are an attempt to measure how many documents were viewed by customers on your Web site. Documents usually include:
- Web pages, like: .html, .htm, .asp, .php files
- Documents, like: .doc, .xls, .pdf
- Script files, like: .cgi, .pl
- Plain text files, like: .txt
Files that are generally considered "part" of a Web page, but not the complete content segment themselves are not usually considered a pageview. This includes images, scripts, CSS, and sometimes sound and video files.
Pageviews are used to convey the popularity of your Web site or page. They are usually what someone means when they say their site gets "a lot of hits". Pageviews do not represent the number of people visiting your site. For that you need to measure
Visits or Sessions or User Sessions
A visit is a collection of documents viewed by a given user-agent and IP address combination (or if you have logins, the actual customer logged in) during a pre-defined unit of time. In other words, a visit is an attempt to quantify how one given person wanders through your Web site. A visit attempts to measure the actions of a person rather than the specific technical details of the data downloaded.
Typically, visits are measured as any amount of clicks within 30 minutes on the same site. For example, if I go to your Web site and then take a 20 minute coffee break, then come back and click on some links on your site, that would still be considered one visit. The idea is that any site visitor who has not clicked on a link within 30 minutes has actually left the site.
The flaw in this logic is that it assumes a very rigid method of browsing sites: namely that people go to a site, click through 3-6 pages and then leave. This may be the case for some readers, but consider a person browsing at work. He might start his browsing and then get interrupted by a phone call. 45 minutes later he comes back to his computer and continues browsing where he left off. By the strict methodology of visit calculation, his activity would count as 2 visits to the site, even though from his point of view he never left.
This isn't a serious flaw, but it is important to know what you are measuring, and that it is only an approximation of reality.
A unique visitor is a person (usually defined by user-agent and IP) who has come to your Web site within a pre-defined period of time. These are the actual people visiting your site and they can only be counted once during your time frame. Your time frame can be every day, every week, every month, the school year, or any other period of time that you define.
If I visit your site once today and again two days from now and your measurement timeframe is 1 week, then I would be counted once. If your measurement were daily, then I would be counted for each day I viewed your site.