Originally Posted By: Quattro Pete
I don't use Blackstone personally, but in their defense, isn't trending analysis what's most important when it comes to these $20 UOAs? I don't see how consistently slightly reduced ad pack levels can do much harm when it comes to the big picture.
Also, they only compared Blackstone results against one other lab, which I'm guessing they're affiliated with. That only proves that the two labs are different and does not really prove which one is correct (probably neither). It'd be more credible if they sent samples to 5-10 different labs for comparison.
Trending is the important thing. However, people do compare add packs and make decisions based on this, right or wrong.
Accuracy is important. What if the lab runs on the low side, makes some adjustment - now they run on the high side, or even in the middle. What the heck good is that?
SW labs is an accredited lab that most everyone (including Amsoil) uses when they want independent verification. Smart for Brad Penn to choose them. They are an accredited lab. Probably many here should learn what that means. If you send the sample to "5-10 different labs" that are not accredited, it would be futile - the results would be a loosely spread pattern. If you send it to accredited labs, there would be a fairly tight pattern with accountable standard error, and a mean and sd that actually would be useful.