Google Analytics guide, part 3

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This post is part of a series.  You can find part 1 here and part 2 here.

In this instalment, we'll be looking at how to compare different statistics. I've decided to focus on just the one topic this time so we can cover it in a bit more detail.

Comparing statistics

This is an extremely handy feature, but it's a little more tricky to use as you have to do things in a very specific order. First, go to the Dashboard and find the date range in the top right corner. Click on the arrow to expand the date range.

The first thing you need to do is check whether the dates are already as you want them. We're going to look at the stats for March and compare them to February. The date range needs to start on March 1st and end on March 31st. If this isn't what you see, click on the 1st of March - this will highlight just that date. Now click on the 31st. You'll see that the entire month is highlighted and the date range is updated to reflect this. Here's a screenshot to show you what I mean.

Next, we need to select the second set of dates so we can get a comparison. Just above the Apply button, you'll see a "Compare to Past" checkbox. Tick this box.

The calendar should now have a second date range, highlighted in green instead of blue. February is a shorter month than March, so the date range runs from January 29th to February 28th. This isn't exactly what we want, so click on the 1st of February - as before, you'll see that just the 1st is selected. Now select February 28th.  Your calendar should now look like this:

Just before we continue, note the message beneath the Apply button: "Date ranges are different lengths". This is one problem with comparing months, because not all months have the same number of days. Also, it might not be a great comparison because the 1st of each month may fall on a different day - so you might compare Monday the 1st with Sunday the 1st. That's not particularly useful.

You may find it easier to look at a four week period, i.e. Monday to Sunday, as that way you can compare the same days in each period. For now though, let's stick to comparing February and March. Click the Apply button and watch what happens.

How good is that?!

Just above the graph you'll see a legend - this tells you which line is which. So, the green line is February and the blue line is March. As you can see, the green line ends early because February has fewer days than March.

Beneath the graph you'll see some percentages - a green percentage indicates something you've improved, while a red percentage means the stat isn't as good for the second month as the first. For instance, in this screenshot, the bounce rate has improved by 9.86% but new visits are down by 10.69%.

However, we need to remember that there are more days in the March date range. So let's see what happens if we try a couple of four week date ranges.

Go back to the calendar and choose the following date ranges:

First date range: March 1st, 2009 to March 28th, 2009
Second date range: February 1st, 2009 to February 28th, 2009

Because the date ranges are both for four week periods, you'll notice that selecting the first date range automatically selects the second. Here's the resulting graph for this site:

That's better. Now we're comparing two date ranges of the same length.

Generally speaking, it's easier to analyse your stats if you think week to week and month to month. To compare statistics, you have to think about what you're comparing. Otherwise, it's like comparing two weeks worth of comments when you wrote 3 posts one week and 7 posts the next. It's not a fair comparison. Level the playing field, and the comparison makes sense.

What do you think?

Do you now understand how to use date ranges?
Are you seeing how much Google Analytics can do?

Posted by Ben on April 28, 2009 10:40 | Permalink | Hits: 275
Tags: google analytics, statistics

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