A Standard for Auditing
Web Site Traffic
I/PRO, Internet Profiles Corporation
444 Spear Street, Suite 200
San Francisco CA 94105
tel: 415-512-7470
fax: 415-512-7996
email: info@ipro.com
Web: www.ipro.com
IAS: the I/PRO Audit Standard for web sites
Table of contents
A STANDARD FOR AUDITING WEB SITE TRAFFIC ......................... 4
Introduction .............................................................................4
What is an Audit? ........................................................................... 4
What is the I/PRO Audit Standard?............................................... 4
Audit frequency............................................................................... 4
What are the elements of an IAS-compliant Audit?........................5
What doesn’t an Audit consider?.................................................... 6
THE IAS AUDIT PROCESS ................................................................ 7
1. Web log file transfer ..............................................................7
1.1 Raw Hits .....................................................................................7
2. Pre-audit processing .............................................................7
2.1 Qualified Hits .............................................................................7
2.2 Qualified Pages ..........................................................................7
2.3 Visits ......................................................................................... 8
2.4 Visit Length............................................................................... 8
2.5 Unique Visitors ......................................................................... 8
2.6 Other terms and metrics........................................................... 8
3. Auditing ................................................................................9
3.1 Document Requests .................................................................10
3.1.1 Removal of blank pages ............................................10
3.1.2 Removal of redirection pages...................................10
3.1.3 Removal of administrative/test pages..................... 11
3.1.4 Removal of custom error web pages........................ 11
3.1.5 Removal of other non-viewable files ........................ 11
3.2 Page Requests .......................................................................... 11
3.2.1 Multiple frames pages reduced to one ..................... 12
3.2.2 Removal of WAP and PDA pages ............................ 12
3.2.3 Removal of passive pages ........................................12
3.2.4 Removal of other error web pages .......................... 13
3.2.5 Removal of include files............................................ 13
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3.3 Special Requests ......................................................................14
APPENDIX A: SUMMARY OF EXCLUSIONS....................................15
APPENDIX B: DEFINITIONS ...........................................................16
Audit ..............................................................................................16
Audit Agency..................................................................................16
Audit Analyst .................................................................................16
browser caching .............................................................................16
Census-Based Audit .......................................................................16
click ................................................................................................16
co-branded partner site .................................................................16
Cookie ............................................................................................ 17
Document Request ........................................................................ 17
File Request ................................................................................... 17
Frequency ...................................................................................... 17
Hit .................................................................................................. 17
HTML............................................................................................. 17
IP address ...................................................................................... 17
Page Request..................................................................................18
Page View .......................................................................................18
profile.............................................................................................18
proxy caching.................................................................................18
proxy server ...................................................................................18
push................................................................................................18
Qualified Hit ..................................................................................18
Qualified Page ................................................................................18
Raw Hit ..........................................................................................19
Reach .............................................................................................19
Request ..........................................................................................19
Special Request ..............................................................................19
Unique Visitor................................................................................19
URL ................................................................................................19
user.................................................................................................19
Visit ................................................................................................19
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Visit Length................................................................................... 20
web browser .................................................................................. 20
web log .......................................................................................... 20
web page ....................................................................................... 20
web server ..................................................................................... 20
web site ......................................................................................... 20
APPENDIX C: SOURCES ..................................................................21
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A standard for auditing web site traffic
Note: terms that first appear in italics are linked to the definitions in
Appendix B; sources for some of these definitions are presented in Appendix C.
Those terms that are capitalized are directly specific to web log files and the
Audit standard; those in lower case are more general to the Web. Web log or
Audit specific terms in lower case are used in their more general meaning.
Introduction
What is an Audit?
This document outlines a standard for auditing web site traffic. The purpose of
an Audit is to report not on what a web site serves, but what its visitors see.
Audits provide management, investors, advertisers, and others with a credible
measure of a web site’s traffic. A web site Audit is a manual validation of traffic
by an independent organization (the Audit Agency). Items that an Audit excludes
are discussed in the main body of this document; a single list is presented in
Appendix A.
What is the I/PRO Audit Standard?
The I/PRO Audit Standard (IAS) is the foundation for I/PRO’s I/AUDIT product
line that evolves and improves with the Web and its technologies. The IAS is an
evolution of proposed guidelines formulated in 1997 by the Interactive
Advertising Bureau (IAB, formerly the Internet Advertising Bureau) and
subsequently extended by FAST (Future of Advertising Stakeholders; now
DMC2, Digital Marketing and Commerce Coalition). IAS makes possible the
most consistent and accurate reporting of traffic that can be compared across the
broadest range of web sites.
Audit frequency
IAS uses the Census-Based Audit method in which all web site traffic is
examined. No sampling or extrapolation is allowed in a Census-Based Audit. For
instance, IAS does not allow several days to represent a month, a month to
represent a quarter, or several months to represent a year. Web site Audits are
ideally conducted on a monthly basis. Greater frequency is possible; however, the
manual work required by an Audit Analyst and described in section 3 generally
makes more frequent Audits cost prohibitive.
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What are the elements of an IAS-compliant Audit?
Web site Audits begin with a “raw” web log file recorded by a web server. These
web logs contain a record (or Hit) of each file that the web server serves to a user
via a web browser. These files include the following.
•
HTML files (.htm, .html)
•
Server side code that generates HTML (.cgi, .jsp, .asp, .cfm, .php, …)
•
Framesets (.frm)
•
Images (.gif, .jpg, ,jpeg, .bmp, …)
•
Multimedia files (.mpg, .mpeg, .mp3, .wav, .swf, …)
•
Stylesheets (.css)
•
Customized web site extensions
For each file, the web log may record the following information depending on the
web server software and the web log file format selected.
•
The file requested
•
The time and date that the file was served
•
The Cookie (unique identifier) accepted by the user
•
The IP address to whom the file was served
•
The URL that the visitor came from (if any)
•
The success of the delivery of the file (the status code)
•
The user’s operating system and web browser type
These web logs are transferred to the audit agency. A pre-audit processing stage
is applied to turn Raw Hits into Qualified Hits and then Qualified Pages. Counts
for Visits, Visit Length, and Unique Visitors are derived from Qualified Pages.
The auditing stage consists of a manual review of the remaining pages to remove
those that are not valid, resulting in either a Document Requests or Page
Requests metric. A detailed description of the transfer, pre-processing, and
auditing stages is given in the main body of this document. Appendix B contains
definitions for important terms.
•
−
Web log file transfer
Raw Hits
−
•
Pre-audit processing stage
−
−
Auditing stage
Document Requests
−
−
Page Requests
Qualified Hits
Qualified Pages
−
Visits
Visit Length
−
Unique Visitors
−
•
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What doesn’t an Audit consider?
Web logs are the starting point of a web site Audit. As such, Audits cannot
account for web site activity that does not make it into a web log. Two examples
of such activity are the result of caching: browser caching and proxy caching.
With browser caching, a user’s computer stores pages on its own hard disk. If the
user returns to these pages from the same computer and the pages have not
changed, they will be served by the web browser and not the web server, with the
result that no new activity will be recorded in the web log.
With proxy caching, a similar effect happens. A web page is not stored locally on
the user’s computer, but instead on a “gateway” computer (for instance, within
the user’s company) still separate from the web server. Again, no activity will be
reported in the web logs.
To the extent that caching is enabled at the browser or proxy level and not
disabled by the web site (a technique called “cache busting”), the result will be an
undercounting of traffic by the Audit. Unlike a financial audit, however, such
undercounting is allowed—in essence, undercounts lead to a more conservative
assessment of a web site’s performance.
Finally, Audits cannot determine if a user actually sees an object. If the user
clicks on to another web page, object such as graphics or multimedia files on the
current page may not be fully loaded and will therefore not appear in the web log.
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The IAS audit process
1. Web log file transfer
An Audit starts with a “raw” web log file. The file must be secure during
generation, transfer, and storage at both the web site and the Audit Agency. The
timing of the transfer does not impact the accuracy of the Audit: data may be
captured in real time, hourly, daily, or otherwise.
1.1 Raw Hits
Raw Hits represent the total number of Requests that are logged by the web
server. As such, Raw Hits include requests for HTML pages, images, multimedia
files, style sheets, and other files.
2. Pre-audit processing
The steps described below outline the removal of items from the Raw Hits
number prior to the auditing stage.
2.1 Qualified Hits
•
Qualified Hit exclusions
Removal of invalid status code pages
−
Removal of internal traffic pages
−
Removal of spider and robot pages
−
Qualified Hits are a subset of Raw Hits. The total number of Qualified Hits
represents the number of Raw Hits minus the number of Hits with invalid status
codes, the number of Hits generated by internal and affiliated IP addresses, and
the number of Hits generated from IP addresses of known spiders and robots.
Co-branded data (for instance, classified ads supplied by an outside party) that is
presented as that of a web site is not excluded from Qualified Hits or downstream
metrics such as Qualified Pages, Document Requests, or Page Requests. Server
status codes in the 200 class and 304 are considered valid. All other status codes
including but not limited to 301-303 (redirection), 404 (page not found), and
500 (internal server error) are considered to be invalid and excluded from the
Qualified Hits number.
2.2 Qualified Pages
•
Qualified Page exclusions
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−
Removal of non-HTML generating pages (images, multimedia files,
style sheets, etc.)
Qualified Pages (also called Page Views) are a subset of Qualified Hits. The
number of Qualified Pages is the number of Qualified Hits minus the number of
Hits recorded for files that have a file extension known not to generate HTML:
for instance, .jpg, .class, .gif, .mp3, and so on. Qualified Pages are the basis for
calculating several important metrics: Visits, Visit Length, and Unique Visitors.
2.3 Visits
Visits represent the number of times that users come to a web site. A Visit is
defined by a series of Qualified Pages served by a web server without 30 minutes
of inactivity. That is, Requests for two Qualified Pages separated by 25 minutes of
inactivity will count as a single Visit, whereas two similar Requests separated by
35 minutes of inactivity will be recorded as two Visits. Visits are not the same as
Unique Visitors (see the next section) because a Unique Visitor can make many
Visits within the time period being audited (e.g., a month).
2.4 Visit Length
Visit Length is the difference in date/time stamp of the first and last web pages
that make up a Visit.
2.5 Unique Visitors
A Unique Visitor is a unique web browser profile from which a user visits a web
site during a specific time period (for instance, a month) . To identify a Unique
Visitor, a web site needs to serve a unique identifier such as a Cookie.
A given web browser on a single computer may have more than one such profile,
and there may be more than one web browser on a single computer. Such a
profile may be used by one or more users. Conversely, a user may visit a web site
from more than one profile (either on one computer or on multiple computers).
In the former case, a single Unique Visitor will be counted even when there is
more than one user. In the latter case, each computer will result in a separate
Unique Visitor even though there is only one user.
2.6 Other terms and metrics
•
Reach
•
Frequency
Visits per Unique Visitor
−
Page Requests per Unique Visitor
−
−
Page Requests per Visit
The number of Unique Visitors in a period is also known as Reach. Another
common term is Frequency, which is a measure of the number of times that the
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average Unique Visitor visits a site in the period. Frequency can be expressed
(always for a given period) as the number of Visits per Unique Visitor, the
number of Page Requests per Unique Visitor, or the number of Page Requests
per Visit.
3. Auditing
Qualified Pages are the starting point for the auditing stage. IAS Audits report
one or more of the following metrics.
•
Document Requests
•
Page Requests
•
Special Requests
Each of these items is discussed in more detail in the following sections.
The number of Qualified Pages usually does not equal the number of Document
Requests or Page Requests reported on in an Audit. Audit analysts start with the
list of Qualified Pages and review them by directly visiting the web pages to see if
they are viewable or not. Upon review, audit analysts often find Requests made
that are not valid. Requests that are not valid are manually excluded from the
number of Qualified Pages. The final result is an audited number of either
Document Requests or Page Requests. Document requests contain more
information about different kinds of site activity, but are a less accurate (on the
high side) measure of the number of distinct pages that users see.
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3.1 Document Requests
•
Document Request exclusions
−
Removal of blank pages
−
Removal of redirection pages
Removal of administrative/test pages
−
−
−
Removal of custom error web pages
Removal of other non-viewable files
A web page is composed of one or more HTML documents that can call text,
images, or other files. When users go to a web page, their web browser makes
requests to the web server for all of the HTML documents and other files that
create a single viewable page in the web browser window. Document Requests
measure the number of all valid requests to all valid HTML documents that can
make up a web page, including wireless area protocol (WAP) and personal digital
assistant (PDA) pages. Document Requests exclude URLs that are (1) blank, (2)
redirections, (3) administrative/test pages, (4) custom error pages, or (5) any
non-viewable files.
3.1.1 Removal of blank pages
For example, a web page designed with frames requires multiple HTML files to
create one single page within a web browser window. The structure of a framed
page can be outlined as follows.
•
www.clientsite.com/example.html (this is called the frameset file)
Frame: www.clientsite.com/bannerframe.html
−
Image: www.clientsite.com/bannerframe.gif
>
Frame: www.clientsite.com/rightnavframe.html
−
Image: www.clientsite.com/clicktogo.gif
>
−
−
Frame: www.clientsite.com/content.html
Frame: www.clientsite.com/blank.html
At total of 2 requests for image files and 5 requests for HTML files (including
example.html) are made to the web server when a user goes to
www.clientsite.com/example.html. Assuming that all of the requests are valid,
the Audit will count a total of 7 Qualified Hits and 5 Qualified Pages—one
Qualified Page for each of the HTML files requested. An audit analyst then
verifies the HTML files to make sure that they are indeed valid. Upon review, the
analyst finds that blank.html is really a blank file and therefore should not count
as a valid file. The audited result would then be a total of 4 Document Requests.
3.1.2 Removal of redirection pages
A redirection is an automatic action that takes a user to a URL other than the one
that he or she typed or clicked. Redirections generally happen because a URL has
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changed and the change has not been noted by the user or the publisher of the
link to that URL. If not accounted for, redirections will result in two Requests in
the web log: one for the selected URL and one for the URL that the user
ultimately reaches. Under IAS, such redirections only count as a single Document
Request.
3.1.3 Removal of administrative/test pages
Administrative or test files that add no value to a user are excluded from
Document Requests.
3.1.4 Removal of custom error web pages
Custom error web pages are different than Requests that generate status codes
like 404 (“Object not found”), 400 (“bad request”), and 403 (“access denied”).
The 4xx errors are removed as part of the steps going from Raw Hits to Qualified
Hits. Custom error web pages, on the other hand, are pages created by a web
site’s designers to provide the user with information in the look-and-feel of the
site. These pages do not, however, provide the user with what he or she is looking
for. A web site might intercept a 404 error and put up its own custom error web
page. An example of such a page can be seen at www.ipro.com/404_error.asp.
The result of serving such a web page appears in the web log as a valid page and
is tallied as a Qualified Page, but is not counted as a Document Request.
3.1.5 Removal of other non-viewable files
Any other non-viewable file is also removed from becoming a Document Request.
An example of such a non-viewable file might be a WAP or PDA page that is
formatted specifically for a wireless device and not viewable in a traditional web
browser.
3.2 Page Requests
•
Page Request exclusions
−
Multiple frames reduced to one
−
Removal of WAP and PDA pages
−
Removal of passive pages
Removal of other error pages
Removal of include pages
−
−
A web site’s design can directly impact the number of HTML documents
requested from a web server. A Page Request is a metric defined as a way to
compare the number of HTML requests made by users across different web sites,
regardless of the way in which the web sites are designed. The Page Request
count starts with the Document Request count and then removes additional
items.
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3.2.1 Multiple frames pages reduced to one
Looking at the example above of www.clientsite.com/example.html, the audit
analyst would only count 1 of the HTML files requested as a Page Request versus
counting 4 files as Document Requests. If www.clientsite.com/example.html was
made up of 10 frames instead of 4 frames, the number of Page Requests would
still be 1 whereas the number of Document Requests could become higher than 4
if the additional frames are not blank.
3.2.2 Removal of WAP and PDA pages
If viewable in a web browser, WAP and PDA pages count as Document Requests
but not Page Requests. Both types are removed from the Page Requests count.
3.2.3 Removal of passive pages
The Page Request metric is also based on the distinction of active versus passive
Requests. An active Request means that a user specifically requested the web
page that is sent to the web browser by the web server. Web pages can be
designed to auto-refresh with code that instructs the web browser to
automatically re-request that web page from the web server in a specified
number of seconds. Requests made to the web server due to auto-refreshing are
considered passive Requests because the web page is re-requested from the web
server without any additional action from the user. Web pages that auto-refresh
can not counted towards Page Requests unless there is some way to distinguish
which requests to an web page that auto-refreshes are actively made by a user
and which ones are passively made by the web browser on its own. IAS compliant
audits make this distinction as long as the web page has been appropriately
coded.
To continue with the example of www.clientsite.com/example.html, assume that
the source code for example.html contained instructions for the web browser to
auto-refresh every 60 seconds. Since example.html is the frameset file that calls
all of the other HTML files to the web browser, the audit analyst would not count
any of the HTML documents in the example as Page Requests unless
example.html was coded to allow such a counting.
Like auto-refreshing, web pages that are requested from the web server due to a
push cannot be considered Page Requests. The following two paragraphs provide
examples of pushed Requests.
In the first example, a user looks at www.clientsite.com/example.html and
decides to click on a link to read www.clientsite.com/another_example.html.
Before the web browser displays www.clientsite.com/another_example.html, it
loads a full screen advertisement called int_ad.html. This advertisement stays in
the web browser window for 5 seconds. After 5 seconds, the web browser takes
the user to www.clientsite.com/another_example.html, which is the web page
originally requested. The web page int_ad.html (called an “interstitial” as a result
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of its “in between” positioning) was pushed to the web browser and therefore
cannot be counted as a Page Request.
In the second example, the user is reading
www.clientsite.com/another_example.html and clicks on a link to see
www.clientsite.com/more_examples.html. This time, the web browser loads
more_examples.html and a new web browser window also pops up (or under) at
the same time displaying a file called contest_registernow.html. Since both
another_example.html and contestregister_now.html are delivered to browser
windows when the only “actively” requested web page was
another_example.html, contestregister_now.html is considered a passive
Request because it was pushed. In this example contestregister_now.html is a
pushed pop-up window and therefore cannot be counted as a Page Request.
3.2.4 Removal of other error web pages
Similar to custom error web pages as discussed in the Document Request section,
other error web pages are different than Requests that generate 4xx status codes.
Three examples of error web pages are discussed in the following paragraphs.
•
Search errors
•
Form errors
•
Other errors
Search errors: Web pages that inform the user that there was an error (for
instance, an improperly formatted search or a search generating no results) are
not included as Page Requests.
Form errors: Web pages that inform the user that there was an error in filling out
a form are not included as Page Requests.
Other errors: Other error web pages (for instance, one indicating that a chat
room is full) are not included as Page Requests.
3.2.5 Removal of include files
Include files are text files (generally) that are “called” by another web page.
Typically, include files are called by dynamically generated web pages such as
.asp pages (MS Active Server Pages), .adp pages (AOLserver dynamic pages), .cgi
pages (server side script pages), or .shtml pages. Include files are often used to
display information that is used throughout a site: headers, navigation, footers,
addresses, and phone numbers are often implemented with includes.
When verified, includes files often appear as they are a part of a web page, but
they are not a page themselves. They are similar to frames in appearance, but
they are different in that they cannot be detected by looking at either the
document information or the page source code. Therefore, it is impossible to look
at a page and determine if it is made up of include files. The only indicator is to
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find the individual includes files themselves. These files are excluded as part of
the Page Request process.
3.3 Special Requests
If required, Audits can also report on the number of Requests for specific types of
files or specific files themselves. Examples of these files are listed below.
•
File Requests
−
−
•
Image files
Multimedia files
Document Requests
WAP pages
−
PDA pages
−
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Appendix A: Summary of exclusions
Listed below is a summary of the different exclusions throughout the steps of an
IAS Audit. Each is described in more detail in the main body of the document.
•
Qualified Hit exclusions
−
Removal of invalid status code pages
−
Removal of internal traffic pages
Removal of spiders and robots pages
−
•
Qualified Page exclusions
Removal of non-HTML generating pages (images, multimedia files,
−
style sheets, etc.)
•
Document Request exclusions
−
−
−
−
−
•
Removal of blank pages
Removal of redirection pages
Removal of administrative/test pages
Removal of custom error web pages
Removal of other non-viewable files
Page Request exclusions
−
−
−
−
−
Multiple frames reduced to one
Removal of WAP and PDA pages
Removal of passive pages
Removal of other error web pages
Removal of include files
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Appendix B: Definitions
Note: terms that are capitalized are those directly specific to web logs and the
audit standard; those in lower case are more general to the Web. Web log or
audit specific terms in lower case are used in their more general meaning.
Audit
A web site audit is a manual validation of traffic by an Audit Agency. The purpose
of an Audit is a report not on what the web site serves, but what its users see.
Audits provide management, investors, advertisers, and others with a credible
measure of a web site’s traffic. I/PRO’s I/AUDIT service adheres to the IAS
standard discussed in this document.
Audit Agency
An independent organization employing Audit Analysts who perform Audits.
Audit Analyst
A person who performs an Audit.
browser caching
The storage of recently used documents on the hard disk of a user’s computer to
speed browsing of the Web. When a user revisits a web page, depending on their
settings, the web browser may display the document from the local disk rather
than from the web site's web server. As a result, web servers may undercount the
number of times a file has been viewed.
Census-Based Audit
As opposed to an Audit based on the sampling of a subset of data, a CensusBased Audit considers all traffic during the period of the Audit.
click
The interaction of a user with a web site via a web browser, usually by placing the
cursor over a link and pressing (clicking) a button on a mouse or other pointing
device.
co-branded partner site
An independent web site providing content that appears to be that of the web site
being Audited. An example of this would be classified ads compiled by a company
and syndicated to a newspaper web site. The newspaper web site owner may be
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entitled to report this classified section traffic as its own depending on how the
content is presented from an ownership/brand perspective.
Cookie
An alphanumeric identifier sent by a web server to a web browser and stored in
memory or as a text file on a user’s computer. This identifier allows a web site to
remember actions that the user has taken during the current Visit or upon
returning to the web site during a subsequent Visit. There are two types of
Cookies: session and persistent. Session Cookies are stored in memory and
expire when the web browser is closed. Persistent Cookies are stored in a text file
and expire only after a specified period of time. Auditing for Visits and/or Unique
Visitors requires that persistent Cookies be used with expiration times extending
past the life of the Audit.
Document Request
The opportunity for an HTML document to appear in a web browser window as a
direct result of a user’s click with a web site. A click that is followed by a splash
page, an interstitial ad, a web page with several frames, and/or other files may
count as several Document Requests.
File Request
A Request for a file such as an image or multimedia file that is not counted as a
Document Request or a Page Request.
Frequency
Frequency is a measure of the number of times that a given or average Unique
Visitor visits a web site in a given period.
Hit
A single line in a web log recording the serving of files such as HTML documents,
images, or multimedia or other files.
HTML
Hypertext Markup Language, which is the coding method used to format
documents for the Web. HTML can be coded directly or created on the fly by a
scripting or other language.
IP address
A numerical Internet address in the form n.n.n.n that corresponds to a named
domain such as www.ipro.com. IP addresses, and not the named domains, are
almost always recorded in a web log.
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Page Request
The opportunity for an HTML document to appear in a web browser window as a
direct result of a user's click within a web site. Only one file may be counted per
click. A click that is followed by a splash page, an interstitial or pop-up ad, and
then a web page of one or more frames will register only a single Page Request.
Page View
A Page View is the same as a Qualified Page.
profile
A profile is a unique setting within a web browser. Profiles allow different users
to interact differently with the Web. For instance, each user might be registered
with a web site so that he or she can benefit from personalization, stored
passwords, bookmarks, and so on. As a result, each profile will be served a
unique Cookie.
proxy caching
The storing of a downloaded web page by a proxy server. If a proxy server serves
the web page, no Hits will be recorded in the web log of the web server. As a
result, a web server may undercount the number of times a web page has been
viewed.
proxy server
A proxy server works as intermediate storage for a frequently visited web page
and its files so that a user may view them more quickly.
push
A pushed page is one delivered to a user without the user having made an active
Request by clicking on a link.
Qualified Hit
Raw Hits minus those that (a) result in “page not found” and related errors, (b)
originate from an IP address of the web site being audited, and (c) are caused by
search engine or other robots and spiders.
Qualified Page
Qualified Hits minus files (such as images or multimedia files) that do not
generate HTML.
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Raw Hit
All Hits recorded by a web server in a web log.
Reach
Reach is the same as the number of Unique Visitors in a given period.
Request
A File Request, Document Request, Page Request, or Special Request.
Special Request
A special kind of page requested by a wireless (WAP) device, personal digital
assistant (PDA) page, or other non-standard browser equipped hardware.
Unique Visitor
A Unique Visitor is a unique web browser profile from which a user visits a web
site during a specific time period (for instance, a month) . To identify a Unique
Visitor, a web site needs to serve a unique identifier, typically a Cookie. A given
web browser on a single computer may have more than one such profile, and
there may be more than one web browser on a single computer. Such a profile
may be used by one or more users. Conversely, a user may visit a web site from
more than one profile (either on one computer or on multiple computers). In the
former case, a single Unique Visitor will be counted even when there is more
than one user. In the latter case, each computer will result in a separate Unique
Visitor even though there is only one user. The number of Unique Visitors in a
given period is also known as Reach.
URL
Uniform (or universal) resource locater, also known as the address of a web page.
Example URLs include www.ipro.com and www.ipro.com/services/iaudit.asp.
user
A person operating a web browser installed on a computer.
Visit
A series of Requests by a user without 30 consecutive minutes of inactivity. If a
user returns to a web site after more than 30 minutes of inactivity, a separate
Visit will be recorded.
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Visit Length
Visit Length is the difference in date/time stamp of the first and last web page
within a Visit.
web browser
A software program operated by a user to access a web page or a web site.
web log
A file, usually plain text, generated by a web server. A web log records all of the
files (HTML files, images, multimedia files, and so on) that the web server
delivers as well as information about each file served: the time, the requesting IP
address, the referring URL, and so on.
web page
A collection of electronic files that includes text, images, multimedia items, and
others. A web page is a “single entity” in the same manner as a print page,
regardless of how many files make it up or how much scrolling is required to see
it all. One or more web pages constitutes a web site, which is delivered to the web
browser of a user via a web server.
web server
A computer installed with software (e.g., Apache, Microsoft IIS) that allows web
pages to be delivered to the web browser of a user.
web site
A collection of one or more linked web pages that exist within a domain such as
www.ipro.com. Alternately, the business that owns the web site. For the purpose
of an Audit, a web site may also be a collection (property) of multiple web sites.
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Appendix C: Sources
“Web Measurement Standard Definitions,” Internet Industry Initiative (III), July
30, 2001.
“Measure Definitions,” netScore Traffic Measurement Report, May 2001.
“Web Measurement Standards,” International Federation of Audit Bureaux of
Circulations (IFABC), February 2, 2001.
“Metrics and Methodology,” Interactive Audit Bureau (IAB), September 15, 1997.
“Metrics and Methodology: A Recommendation to the FAST Forward Audit Subcommittee,” Future of Advertising Stakeholders (FAST), undated but following
September 15, 1997 IAB document.
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