How to tell if your results are significant – a practical guide

Marketers frequently face a situation like this: In a survey it is found that 57% of women prefer product A, while 60% of men prefer product B.

In this article I will show how marketers – using only simple statistical analysis tools available in Microsoft Excel – can quickly and easily decide whether or not they can draw meaningful conclusions from such a result, or whether they may be making fatal mistakes by interpreting random noise as valid data.

stats mofo

Marketers frequently face a situation like this: In a survey it is found that 57% of women prefer product A, while 60% of men prefer product B.

Some marketers will just go “Great, statistics prove that women prefer product A, and men prefer product B. We’ll market product A to women then and product B to men.”.

But is this really always a valid conclusion? Couldn’t it also be that the difference is purely coincidental? After all, we haven’t asked all people, but only a subset of people: those participating in our survey. So maybe if we took another sample, and asked different people, the results would be different? May well be!

Statistics to the rescue!

As is often the case, statistics can provide a solution. Before delving into the details, let’s look at another, more formalized example. Dice!

Suppose we take two dice, and we want to know if one of them is loaded, i.e., we want to know if one of the dice yields better values than the other. Let’s start by throwing them 10 times each. This is what the results may look like:

Example 10 dice

Well. What do we get? Let’s look at the mean value for each die. As a reminder, if the two dice were fair dice, there would be an equal likelihood of one in six for each number to turn up. More formally, the expected value would be 3.5 (=1/6*1+1/6*2+…+1/6*6).

So what do we get for our dice? For die 1, the mean is (4+4+4+…+3)/10 = 4.40, the mean for die 2 is (5+2+1+…+1)/10 = 3.20.

So is die 1 better than die 2? Well the average is higher, of course, but as you will intuitively suspect, 10 throws is quite a small number of throws to draw any meaningful conclusions.

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Why the new Spotify UI makes no sense. A rant.

A while back I’ve been whining about the lack of a decent music collection management Spotify. In the past months, Spotify has worked quite a bit on their UI and have changed their interface a lot. Sometimes for the better, sometimes for the worse. Bottom line however: the music collection management is still freaking useless.

Disclaimer: the following contains a lot of SHOUTING and CURSING. Sorry about that. But I’m really really passionate about my music player, and just hate to see that Spotify, which I otherwise LOVE, can’t seem to get their sh*t together.

So here we go: First, there’s the SONGS tab:

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Last.fm partners up with Spotify to offer on demand plays

Spotify Last.fmGreat news! Last.fm partners up with Spotify to again offer on-demand plays:

We’ve teamed up with Spotify to bring their entire catalogue, on demand, to the world’s leading music recommendation service.

About two years ago, Last.fm had dropped their on-demand plays, to “focus on the features that make Last.fm unique — scrobbling, personalised radio, and being the online home for your music taste”, or, put differently, CBS wanted to cut the costs so they decided to save the royalties.

Well I’m glad they’ve finally come up with this solution! The integration works pretty well, too: if you hit the play button on last.fm, Spotify is opened in the background to play the track. Smooth. What’s great, too, ist that on a “Top Tracks” list, such as the one below, the entire list is put in a Spotify-playlist.

PlayOnLastFM

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Spotiamp – it really whips the llama’s ass.

Found this little gem today:

Spotiamp

Spotiamp is a little program that lets you login to your Spotify account and play your playlists and more.

Apart from being nostalgic, it actually is a great player! The minimalistic design is timeless of course, but it is also a very fast player. The download is less than 500kb, it loads up in no time, and hardly uses any ressources. Plus, there’s any equalizer (which is dearly missed in Spotify).

In other words – it really whips the llama’s ass!

 

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