When Metrics Give you Lemons

Anyone that’s paying attention knows that we’re inundated with ranks, wherever we turn. Alexa, Compete, Domain Authority, Trust Flow… all sorts of warm, fuzzy words, initials, bars and numbers, all able to make you feel good, sad or confused.

So which of these metrics are of any value?

None of them. Or all of them. Take your choice.

The thing about such metrics is that they’re all different. Some are looking at different things, it’s a pretty sure bet that they all apply different weight to various factors. So comparing Trust Flow to Domain Authority is like judging how sour a lemon may be, by the number of apples harvested from a neighboring tree… a totally freakin’ useless exercise.

But… you can rate the sourness of one lemon, compared to another, provided the same person is doing the judging. Two different people will normally rate the sourness level of the same lemon differently, though. If you have those two raters follow a 3 point scale, not at all sour, medium sour, extremely sour, you’ll still be depending upon their individual tastes and tolerances. But their findings probably won’t differ a lot.

However, give them a 100 point scale, and you’ll find very few common points (the latter, though, will actually be more accurate, in some regards).

If you want to compare one lemon against another, then it doesn’t really matter so much what scale you use, as long as you’re comparing the rating given one lemon to the rating given another, by the same rater, following the same criteria.

Any such ratings you may see for your site are being assigned by different raters, using different scales, with different weighting. The only value they can offer is when you compare two very similar pages’ ratings with the same metric. And even that value is highly questionable.

If both pages are similar in every regard (and even with cloned pages, they won’t be… think fingerprints – no two alike), then the comparison might be a reasonable approximation of their relative standing. But in reality, the only usable value in those metrics is when you’re comparing today’s rating of a page against tomorrow’s rating of the same page. That will at least give you an indication of which direction things are moving in. For that exercise, one’s about as good (or useless) as another.

Beyond that, though, forget it!