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Beginners Guide to Maths and Stats behind Web Analytics

105 points by ZanderEarth32 14y ago

louwhopley 14y ago
Awesome! This clears up stats and speaking statistics a lot for me. Thank you.
pseut 14y ago
WTF? This was a somewhat incoherent list of "stats stuff"; I especially liked the equation: signal confidence = ------ x \sqrt(sample size) noise (none of the terms in the 'equation' were defined beforehand) which was led into by 'so when someone says “is your result statistically significant?” then it means he is really asking “What is the likely hood that your result has not occurred by chance”' No no no no no no no no no no non. Edit: corrected despair-induced typos.
kappaloris 14y ago
any source for people who know some statistical theory but know almost nothing about how it is applied to web analytics?
- disgruntledphd2 14y ago
  There isn't one, or at least there wasn't when I went looking (almost PhD quantitative psychologist now working in web analytics). I was thinking of starting a blog series, possibly a book called Web Analytics for Nerds or something. That's at least a month or two (95 int 1-12 months) off though.
  - pseut 14y ago
    Do it!
  - tomrod 14y ago
    I'd love to correspond. ABD econ here, still in the grad game for another year. Ping me if you're interested.
jakozaur 14y ago
In real world the statistics is usually the most useful part of math. Analysing data without some basic statistics lead often to erroneous conclusions. What surprise me, that it doesn't get attention it deserves at pre-university education. A lot of lessons in math are about geometry, algebra, etc. which are a great way to learn logical and abstract thinking, but aren't as useful as statistics.
shanellem 14y ago
Awesome post! Knowing how to use analytic suites is one thing, but knowing how to accurately interpret the data is another.
vtuulos 14y ago
Shameless plug: https://bitdeli.com https://bitdeli.com lets you put theory into practice - you can build your own web analytics in plain and simple Python. Feel free to ping me if you need help getting started (or a longer trial :)
deleted 14y ago
[deleted]
dkarl 14y ago
Q1. When your website conversion rate jumps from 10% to 12% then is it 2% rise in conversion rate or 20% rise in conversion rate? This question doesn't have a clear answer, because the values are already percentages. Imagine the original numbers refer to apples. First there were 10 apples, then 12 apples. The absolute increase is 2 apples; the relative increase is 20%. Obviously, if you say "the increase is __ apples" or "the increase is __ %" there's only one right way to replace the blanks with numbers. But since 10 and 12 are already percentages, the absolute and relative changes would be stated as "the increase is 2%" (absolute increase) and "the increase is 20%" (relative increase.) They mean different things, but they're both correct statements if interpreted correctly. In practice, people will expect one and interpret the other as wrong. Knowing which one they expect is not a matter of statistics.
- pseut 14y ago
  It's a change of two "percentage points," not 2%. With the right vocabulary, there's no ambiguity.
  - dkarl 14y ago
    If you rely on people making the same precise distinction between "percent" and "percentage point" that you do, then you'll have more misunderstandings rather than fewer. It's like "next Friday." If today is Monday the 3rd and I say "next Friday," I don't rely on anyone outside my immediate family understanding that I mean Friday the 14th, since many people understand it to mean Friday the 7th.
    - pseut 14y ago
      I "rely" on the person saying that it went from 10% to 12%. I'll refer to such a change as a 2 percentage point change, but if the other person calls it the wrong thing, I don't really care. I'd be much more concerned about someone getting worked up about the semantics of the it and ignoring the context of the numbers. E.g. If they want to call it a 20% change and leave it at that, the misuse of terminology is the least of our problems. Witness: http://xkcd.com/1102/ http://xkcd.com/1102/
alexatkeplar 14y ago
If you want to have a go rolling your own web analytics calculations, I would recommend setting up SnowPlow (https://github.com/snowplow/snowplow https://github.com/snowplow/snowplow) and then following through the SnowPlow Web Analyst's Cookbook (start with the simple recipes here: http://snowplowanalytics.com/analytics/basic-recipes.html http://snowplowanalytics.com/analytics/basic-recipes.html). Here's a simple example for unique visitors by month: SELECT YEAR(dt), MONTH(dt), COUNT(DISTINCT(user_id)) FROM events GROUP BY YEAR(dt), MONTH(dt) ;
prashantganti 14y ago
Nice article. It could have done with a better example for %difference. %difference is used when neither value is more important or topical than the other.
tomrod 14y ago
What is the pay rate for someone who knows far, far more statistics than this, and can communicate at a coherent level?
- sctechie 14y ago
  "Data science" is a hot thing right now. If your technical / design abilities match your stats knowledge, you could pull 6 figures easily depending on the market you're in. http://en.wikipedia.org/wiki/Data_science http://en.wikipedia.org/wiki/Data_science
- pseut 14y ago
  I think economics consulting firms pay > $150k for recently graduated phds -- just looked at your cv... you must have former classmates working for NERA, bates-white, etc. who could give you specifics. Given your research interests that seems like a natural fit.

105 points by ZanderEarth32 14y ago

Awesome! This clears up stats and speaking statistics a lot for me. Thank you.

pseut 14y ago

WTF? This was a somewhat incoherent list of "stats stuff"; I especially liked the equation: signal confidence = ------ x \sqrt(sample size) noise (none of the terms in the 'equation' were defined beforehand) which was led into by 'so when someone says “is your result statistically significant?” then it means he is really asking “What is the likely hood that your result has not occurred by chance”' No no no no no no no no no no non. Edit: corrected despair-induced typos.

kappaloris 14y ago

any source for people who know some statistical theory but know almost nothing about how it is applied to web analytics?

disgruntledphd2 14y ago
There isn't one, or at least there wasn't when I went looking (almost PhD quantitative psychologist now working in web analytics). I was thinking of starting a blog series, possibly a book called Web Analytics for Nerds or something. That's at least a month or two (95 int 1-12 months) off though.
- pseut 14y ago
  Do it!
- tomrod 14y ago
  I'd love to correspond. ABD econ here, still in the grad game for another year. Ping me if you're interested.

jakozaur 14y ago

In real world the statistics is usually the most useful part of math. Analysing data without some basic statistics lead often to erroneous conclusions. What surprise me, that it doesn't get attention it deserves at pre-university education. A lot of lessons in math are about geometry, algebra, etc. which are a great way to learn logical and abstract thinking, but aren't as useful as statistics.

shanellem 14y ago

Awesome post! Knowing how to use analytic suites is one thing, but knowing how to accurately interpret the data is another.

vtuulos 14y ago

Shameless plug: https://bitdeli.com https://bitdeli.com lets you put theory into practice - you can build your own web analytics in plain and simple Python. Feel free to ping me if you need help getting started (or a longer trial :)

deleted 14y ago

[deleted]

dkarl 14y ago

Q1. When your website conversion rate jumps from 10% to 12% then is it 2% rise in conversion rate or 20% rise in conversion rate? This question doesn't have a clear answer, because the values are already percentages. Imagine the original numbers refer to apples. First there were 10 apples, then 12 apples. The absolute increase is 2 apples; the relative increase is 20%. Obviously, if you say "the increase is __ apples" or "the increase is __ %" there's only one right way to replace the blanks with numbers. But since 10 and 12 are already percentages, the absolute and relative changes would be stated as "the increase is 2%" (absolute increase) and "the increase is 20%" (relative increase.) They mean different things, but they're both correct statements if interpreted correctly. In practice, people will expect one and interpret the other as wrong. Knowing which one they expect is not a matter of statistics.

pseut 14y ago
It's a change of two "percentage points," not 2%. With the right vocabulary, there's no ambiguity.
- dkarl 14y ago
  If you rely on people making the same precise distinction between "percent" and "percentage point" that you do, then you'll have more misunderstandings rather than fewer. It's like "next Friday." If today is Monday the 3rd and I say "next Friday," I don't rely on anyone outside my immediate family understanding that I mean Friday the 14th, since many people understand it to mean Friday the 7th.
  - pseut 14y ago
    I "rely" on the person saying that it went from 10% to 12%. I'll refer to such a change as a 2 percentage point change, but if the other person calls it the wrong thing, I don't really care. I'd be much more concerned about someone getting worked up about the semantics of the it and ignoring the context of the numbers. E.g. If they want to call it a 20% change and leave it at that, the misuse of terminology is the least of our problems. Witness: http://xkcd.com/1102/ http://xkcd.com/1102/

alexatkeplar 14y ago

If you want to have a go rolling your own web analytics calculations, I would recommend setting up SnowPlow (https://github.com/snowplow/snowplow https://github.com/snowplow/snowplow) and then following through the SnowPlow Web Analyst's Cookbook (start with the simple recipes here: http://snowplowanalytics.com/analytics/basic-recipes.html http://snowplowanalytics.com/analytics/basic-recipes.html). Here's a simple example for unique visitors by month: SELECT YEAR(dt), MONTH(dt), COUNT(DISTINCT(user_id)) FROM events GROUP BY YEAR(dt), MONTH(dt) ;

prashantganti 14y ago

Nice article. It could have done with a better example for %difference. %difference is used when neither value is more important or topical than the other.

tomrod 14y ago

What is the pay rate for someone who knows far, far more statistics than this, and can communicate at a coherent level?

sctechie 14y ago
"Data science" is a hot thing right now. If your technical / design abilities match your stats knowledge, you could pull 6 figures easily depending on the market you're in. http://en.wikipedia.org/wiki/Data_science http://en.wikipedia.org/wiki/Data_science
pseut 14y ago
I think economics consulting firms pay > $150k for recently graduated phds -- just looked at your cv... you must have former classmates working for NERA, bates-white, etc. who could give you specifics. Given your research interests that seems like a natural fit.