Articles in the Benchmarking & Measuring Success Category

March 4 2009

The difference between the Linear and the Logarithmic Scales

By now, mostly everyone has tried using a Motion Chart by clicking on the “Visualize” button, toward the top of several Google Analytics reports at least one time.

…What? What do you mean “No!“? What do you mean “I didn’t even know it existed!“? Well, if you haven’t taken a look, I strongly suggest doing so. For example, go to your Traffic Sources >> Keywords report and click on “Visualize” towards the top – you should see something like this:

There you go – you have just been visualized! :). You can increase the number of circles (or “bubbles”) that appear by going back to the regular report and increasing the number of rows, toward the bottom-right of the report table.

One update to Motion Charts that happened a few months ago which flew a bit under the radar was the option for you to define your viewing scale – Linear, or Logarithmic. I can get into a complex mathematical / statistical explanation of the differences between the two – which I’m sure will satisfy some of you – but for the masses, the easiest possible explanation I can use to differentiate the two is:

Linear Scale – Based on Addition
Logarithmic Scale – Based on Multiplication

The first image above is an example of a Motion Chart using the Linear Scale. Notice on the X axis (going from left to right, the “Pages / Visit” metric), the values from left to right increase by 5 on each point – 5, 10, 15, 20, etc… The values in the Y axis (Visits) increase by 100 on each point – 100, 200, 300, and so on.

Now let’s change “Lin” to “Log” and watch what happens to our Motion Chart:

The motion chart data is exactly the same, but much different looking now, is it not? Notice how the bubbles are much more spread out and more “all over the place” using the Logarithmic Scale. The Motion Charts in Google Analytics use what is known as a base 10 sequence, as each point in the scale is multiplied by 10. A little tough to notice here in the X axis (Pages / Visit), but noticeable on the Y axis (Visits) – 1, 10, 100, 1,000, and it continues off the chart infinitely.

When to use the Linear Scale? When to use the Logarithmic Scale?

A good rule of thumb is to use the scale that best shows off your data. If you are only using the motion chart for the top 10 rows of your report, chances are that the linear scale will work just fine. If you’re going to be using 25 or more rows, you’ll most likely find it much easier on the eyes if you use the logarithmic scale. So, less data = linear; more data = logarithmic. But, please, play with the Motion Charts and decide for yourself what’s easier for your chart.

“The Difference Between” Series:

February 19 2009

Wednesday Interview Series: Average Time on Site

Every Wednesday, I sit down and interview different metrics or report sections from Google Analytics. I ask the tough questions – and I expect straight answers! (This, obviously, is a fictional interview. However, if metrics or reports could talk and be interviewed, this is how I imagine their personalities being and how they would answer my questions. Hopefully this will be a fresh, interesting way to learn about the wonderful world of Google Analytics in a unique way).

Joe Teixeira: “Mr. Average Time on Site…how are things?”
Average Time on Site: “…Average…”
JT: “What’s with the sunglasses?”
ATOS: “…It’s bright in here…”
JT: “Well those are just the studio lights…I can have them turned down if you…”
ATOS: “No…it’s cool.”
JT: “Ummm…OK. Well let me ask you my first question. Can you explain to everyone exactly how you are calculated?”
ATOS: [Turns Away in Disgust and Rolls Eyes] “Man…come on, man. Why you gotta play me like that? Everybody knows it’s up to __utmb and __utmc to calculate the difference between the time stamps of each page. I ain’t got nuthin’ to do with any of that.”
JT: “So, two cookies – __utmb and __utmc – they calculate you…”
ATOS: “Yeah, man…”
JT: “…and the difference between each time stamp on each page is the time a user spent on that page…”
ATOS: “Yeah…”
JT: “…and then the Average Time on Site is the sum of all of the time a user – or groups of users – spent on the pages of a site, divided by the number of pages viewed.”
ATOS: “…something like that. If you know all this, how come you’re asking me, man?”
JT: “Because I wanted to hear what you’d have to say about it…”
ATOS: [Becoming more frustrated] “Look, man, this is how it goes down, a’ight? If somebody bounces from a landing page, guess what happens? I become an average of 0:00:00, because there ain’t no second timestamp to go by, so [pointing to the ceiling] the big man upstairs [GA] can’t give me credit for my time. It ain’t my fault, I’m just doing my job around here.”
JT: “So you really have a problem with this. What about people that leave their computers on and go to lunch, or go to a meeting?”
ATOS: “It’s the same thing, except backwards. Let’s say somebody goes to lunch for an hour and they leave they browser on…after 29 minutes of what they like to call “inactivity”, I stop counting. This happens ALL THE TIME, man. It just ain’t right! If they time me out, no second timestamp happens, which again means the average time for that page becomes 0:00:00.”
JT: “What I’m gathering from you is the message you’re trying to convey here is for people who look at you, and use you in their reports and presentations, to take you with a grain of salt…to use your number precariously.”
ATOS: “Well I don’t know what “precariously” means…but yeah, don’t do that.”
JT: “Last week, I talked briefly to Bounce Rate about setVar, and how his change in classification has impacted him. How has the update to setVar affected you?”
ATOS: “Man, it’s about time they did somethin’ about that. setVar ain’t nothing but a greedy metric, man. I’ve been tryin’ to tell people about setVar, and how it was being counted as an interaction hit, but they weren’t listening to me…but finally they took care of some business and straightened things out.”
JT:
“Well, thanks a lot for your time…”
ATOS: “Oh, shoot – we done already?”
JT: “Yeah, I’m sorry…”
ATOS: “C’mon, man…I get paid by the second…”
JT: “Sorry, ATOS…maybe some other time.”
ATOS: “…whatever, man. That’s what everyone always says: “Time”. More time, less time, average time…everyone always wants to know about time. People need to just chill for a second and look at everything else, not just me…”
JT: “Well…thanks again [I start getting up].

Wednesday Interview Series:
February 11, 2009: Bounce Rate

February 11 2009

Wednesday Interview Series: Bounce Rate

Every Wednesday, I sit down and interview different metrics or report sections from Google Analytics. I ask the tough questions – and I expect straight answers! (This, obviously, is a fictional interview. However, if metrics or reports could talk and be interviewed, this is how I imagine their personalities being and how they would answer my questions. Hopefully this will be a fresh, interesting way to learn about the wonderful world of Google Analytics in a unique way).

Joe Teixeira – “Hey there Bounce Rate, how’s it going?”
Bounce Rate – “Hey Joe! Right now I’m doing great and flying low…but tomorrow I may be down on my luck…”
JT – “Well, why do you say that?”
BR – “There’s a reason my name is “Bounce” Rate – sometimes I’m very low and loved by everyone – other times, when I’m a bit higher, I’m scrutinized and examined like a Wall Street executive on Capitol Hill.”
JT – “Well, you’re a very important metric, Bounce Rate. People really seem to love you when you’re low…”
BR – “I know, I know…it’s just…why can’t they always love me, even when I’m high? I mean, I’m just a metric…why can’t more people look at other things, too?”
JT – “Are there any other places that you want people to start paying attention to?”
BR – “Yeah – and I hate to put him on the spot, because we go way back – but people should look at me when they’re looking at Top Landing Pages. I mean, it’s a great place for everyone to find out how effective each one of the pages of their website are as an entry point, as a landing page.”
JT – “So you feel as if people may be looking at you in a way that you feel is not necessarily the best?”
BR – “Oh yeah, absolutely! When people look at me on the Dashboard, they either love me or hate me – there’s never any middle ground. Well, I think people should really go beyond the Dashboard and see me when I’m broken down by each individual landing page or keyword!”
BR – I talked to Top Landing Pages – he agrees with me. It’s hard to get a hold of Keywords now a days, though. A lot of requests for him, you know…”
JT – “Sure, I bet.”
JT – “Let’s move on. What percentage makes you happy? 25%? 30%? 50%?”
BR – “See, there you go. You’re just like everyone else; you want a fixed percentage for me. Why can’t anyone accept me for who I am? Sometimes I can’t be 25% – but that doesn’t mean 25% is too high. Other times I can’t get lower than 60%, but – in a lot of industries – 60% is really good! Yet so many people tell me “I want you to be 15% across the board”, and depending on the site and the industry, I just can’t get that low…I just can’t…”
JT – “I’m sorry – I didn’t mean to hurt your feelings. But you’re so great at pointing out to [most] of us the pages, keywords, and even the site search terms that we need to focus our optimization efforts on…sometimes we get greedy and we want you as low as possible!”
BR – “It’s not like I’m not trying to be low, Joe…I DO try…but there’s nothing I can do when sometimes there are just so many bounces that have to be divided into the number of entrances…if people just focused more on helping me be lower, rather than yelling and cursing at me for not being low enough, I probably would be much lower over time!”
JT – “I agree with you. One final question before I let you go: recently, Google Analytics has decided that your long-time friend, setVar, would no longer be counted as an interaction hit. Have you spoken to setVar at all since the announcement?”
BR – “Yeah, I talked to setVar a few times – he’s sorrier for me than I am for him, because now that he’s not an interaction hit, I’m going to go up at least a few percentage points here and there. But I’m OK – and I’m happy for setVar, you know. I think it’s important that he’s classified and tabulated properly from now on.”
JT – “Thank you, Bounce Rate. Hang in there…”
BR – “OK, thank you…I will…”

Tune in next Wednesday, where my special guest will be the notorious Average Time on Site. You won’t want to miss it!