Sampling is the practice of calculating trends based on a "sample" of the data that's available - not all of it.

Google Analytics samples data to save time and resources. Sampling usually only occurs on larger About.com sites and/or in the busy morning hours in the US.

While sampling doesn't often significantly impact averages like bounce rate, pages/session, and session duration, it will, by definition, cause pageview, session, and other whole numbers to be innacurate.

Sampling occurs more often when pulling data into a tool like ExpertFocus, but it can happen in Google Analytics reports as well. To see if sampling is happening in GA itself, take note of the "% of sessions" note at the top of any GA report. Anything less than 100% implies sampling.

See Google's About Sampled Data and How Sampling Works help documents if you'd like to learn more about sampling in Google Analytics.

Giving the About.com ExpertFocus tool access to your Google Analytics data means just that. ExpertFocus will be able to pull data about your Google Analytics accounts into the tool and display it for you on this and other ExpertFocus pages.

ExpertFocus connects to Google Analytics via OAuth 2.0. No data, including usernames or passwords, are visible to anyone but you even though you see your private data on ExpertFocus.

A pageview is a view of a page that's tracked by Google Analytics.

Repeat views of a page during a single visit, including page refreshes, all count as additional pageviews.

In general, more pageviews is better than less pageviews.

About.com uses Google Analytics to track all of the pages you've authored as well as a number of other pages that appear on your site.

A visit, also called a session, is the collection of activities a user takes on your site - like viewing pages, clicking on share buttons, interracting with ads, etc.

In general, more visits is better than less visits.

A single visit might drive just one pageview (a situation referred to as a bounce) or, hopefully, might drive several pageviews.

A landing page is simply the page on which a visit on your site started.

Session duration, usually reported as average session duration, is the average amount of time visitors spent on your site.

In general, a longer session duration is better than a shorter session duration.

A longer session duration usually means that visitors are engaged with your content and visiting more than one of your pages.

A shorter session duration could mean that visitors aren't interacting with your site very much and/or aren't investing much time in reading your content.

Pages/Session (pages per session) is the average number of pages viewed during a session.

In general, more pages/session is better than less pages/session.

Higher pages/session means that visitors landing on your content are finding more content they're interested in consuming.

Lower pages/session means that visitors that land on your site aren't, for some reason, visiting more of your pages.

Pages/Session is sometimes referred to as average page depth.

Bounce rate is the percentage of visits where a visitor arrived on a page but then didn't go any further.

In general, a lower bounce rate (fewer single-page visits) is better than a higher bounce rate (more single-page visits).

A lower bounce rate tends to imply that visitors are happy with what they found and are sticking around to learn more.

A higher bounce could mean that visitors didn't find what they wanted and/or aren't interested in anything else they see on the page.

Direct traffic is any visit where Google Analytics couldn't identify a source for.

Some direct traffic might be due to someone visiting one of your pages from a bookmark, from inside some mobile apps, via an email (other than an About.com newsletter), or from any number of other hard-to-track sources.

Google Analytics might even classify some search traffic, like visits from Google or Bing searches, as direct due to inconsistencies with how some browsers work.

Other traffic is a visit that Google Analytics can identify a source for but is from somewhere other than search, social, newsletter, or a non-About.com site.

At About.com, most of this "other" traffic is due to paid advertising from About (SEM).

This area in ExpertFocus shows you the page visitors came from only when that page was an About.com site other than yours.

Traffic to pages on your site from other About.com pages is traffic that's already reported by its original, from-outside-About.com source in "Where Yesterday's Visitors Came From."

For example, if Google sent a visitor to widgets.about.com/best-ever-widgets.html and a link on that page sent the visitor to your site, the source is and always has been reported in GA, and in ExpertFocus, as Google.

The tracking that allows you to see your pageviews from other About.com pages was enabled in late May, 2015. Prior to that time, this data will show up as 'zero' in both ExpertFocus and GA.

Hour-by-hour comparisons are great for a finer look at changes yesterday, which you can find in these , , and reports.

See the All Pages report in Google Analytics for a complete list of yesterday's pages by pageview or these , , and reports for more on how your individual page's views are changing over those time periods.

A complete list of the pages your visitors landed on can be found in yesterday's Landing Pages report in Google Analytics.

See yesterday's , , and landing pages reports for more on how the pages by which visitors are entering your site is changing.

See yesterday's Landing Page (Weighted by Bounce Rate) report in Google Analytics to see yesterday's highest-traffic landing pages with the highest bounce rates. These are the articles you should work to improve bounce rate on for the highest return on your time investment.

See these , , and versions of that report to see how the bounce rates on those high-value pieces are changing.

Check out the Bounce Rate Comparison report in Google Analytics to see how the bounce rate of yesterday's landing pages stack up against each other when compared to your site average, and these , , and versions of that report for changes.

Yesterday's Pages/Session Comparison report in Google Analytics shows which pages drive more pageviews per visit compared to your site average.

These , , and report show the same over those timeframes.

Check out Google Analytics' Session Duration Comparison report for how session duration differed between your top landing pages.

That report's , , and versions will show you how time spent on your site by page is changing over time.

See yesterday's Acquisition by Channel report in Google Analytics for more on how yesterday's sources of traffic to your site broke down.

These , , and versions show how the source of your visitors is changing over time.

See yesterday's Organic Search by Source report in Google Analytics for more on the individual search engines that sent traffic to your site.

These , , and versions of that report will show how search engine traffic is changing.

A complete list of yesterday's most visited pages from search can be found in the Organic Search Landing Pages report in Google Analytics.

See that report's , , and versions to see how your content that's popular via search is changing.

See yesterday's Social Network Referrals report in Google Analytics for details about the traffic that each social network sent to your site.

That same report in , , and format will show changes in the traffic each social network is sending you.

A complete list of yesterday's most visited pages from social can be found in the Social Landing Pages report in Google Analytics.

See that report's , , and versions to see how your content that's popular via social is changing.

Your site's Referral Traffic report in Google Analytics will show you how much traffic, in total, each site sent to yours.

These , , and versions of that report will show how traffic from those sites is changing.

A complete list of yesterday's pages that received traffic from other sites can be found in the Referral Traffic Landing Pages report in Google Analytics.

See that report's , , and versions to see how your content that's getting traffic from other sites is changing.

See yesterday's Email by Source report in Google Analytics to see which About.com newsletter sent this traffic to your site.

These , , and versions of that report will show how traffic from the various About.com newsletters is changing over those timeframes.

A complete list of yesterday's most visited pages from newsletters can be found in the Email Landing Pages report in Google Analytics.

See that report's , , and versions to see how your content that's popular via email newsletter is changing.

See all the pages that were visited directly in yesterday's Direct Landing Pages report in Google Analytics.

See that report's , , and versions to see how your content that's being visited directly is changing.

A complete list of yesterday's pages that received traffic from other About.com sites can be found in the About.com Referral URL by Page report in Google Analytics.

See that report's , , and versions to see how your content that's getting traffic from other About.com pages is changing.