Using advance segments or primary dimensions?

[William.Lau]

Hi guys,

I haven't played around with advance segments enough to know the answer to this, so looking for some help.

What I want to track is a keyword through the whole analytics, so I created an advance segment for "KEYWORD". This segment is Include - Keyword - "KEYWORD".

Now when I remove the advance segment and do the following: Traffic Sources - Organic - Primary Dimension - Keyword - "KEYWORD"

The amounts of visits differ a lot. I'm guessing this has to do with sessions? Looking for a clarification on this.

[DaveSottimano]

John Barth has the right answer below. Not sure if I can add much more, except specific instructions:

When you apply advanced segments to reports in GA, the report is automatically sampled. In the top right corner of the interface, you'll either notice a message in a yellow container, or a square that looks like a QR code. The visit counts may never match up exactly, but if you adjust the precision of the report to it's highest level, you'll get much closer.

Explanation from Google documentation:

Apart from the standard reports, users may issue ad-hoc queries to Google Analytics. Common queries include applying advanced segments to standard reports, applying a secondary dimension, or running a custom report. When the front-end issues a query, GA inspects the set of pre-aggregated tables to determine whether the query can be wholly satisfied by existing aggregates. If not, GA goes back to the raw session data to process and compute aggregate data on-the-fly. If the resulting report is sampled, you will always see a yellow box at the top of the report which says: This report is based on N visits.

[john4math]

One thing it could be... in my GA account, almost all advanced segments cause my report data to use sampled data.  If this happens, you'll see a yellow bar off to the right above the graph that says something like "This report is based on 119242 visits (1.16% of visits). Learn more".  As it's taking a sample of a small amount of data and then extrapolating the rest, the numbers it displays in the report here can vary a lot from the true numbers.

The keyword data listed in the Traffic Sources - Organic report when not using an advanced segment won't be sampled, that's the actual true data.

[CleverPhD]

Are you sure you are looking at visits vs unique visits?  I have seen some issues with the custom reports messing up reporting a count of unique visitors.  If you could include some screen shots of the two reports you are comparing that would help.