In my previous blog, I discussed how your laboratory measurements could be precise (the results are reproducible), yet inaccurate (the value is wrong).
Accuracy and Precision
Have you ever noticed that when you are on vacation, your mind relaxes but starts thinking of work-related stuff?It isn’t a bad thing. I know I am supposed to forget about work when I am away but by relaxing, interesting things come to mind at the weirdest times.That is what happened while remote camping back in the...
Importance of Data Normalization in Complex Environmental Data Sets
Prior to making any statistical interference, the distribution of the metal and TSS data is required to be assessed if outlier concentrations are present due to variability in the measurement or experimental error. This pre-processing procedure is referred to as:
The goal of normalization is to...
Find the Right Expert - 3 Things to Look for
In my last post, I discussed the difficulties in finding an expert. I presented some of the differences in the context of the word ‘expert’. The word means something different depending on your perspective and needs.
What Makes an Expert.. an Expert?
How hard is it to find an expert?
I am guessing… it's probably really hard. Not because there are not experts out there.
Natural Soil Salinity… Where can it be found on your site?
This is the question! And the answer is (almost) anywhere!
t-SNE is so last week, all the cool kids are using UMAP now!
Importance of staying on top of trends as a subject matter expert.
I wrote an article discussing the applications of t-distributed stochastic neighbor embedding (t-SNE) as an improved technique for dimensionality reduction and cluster association comparable to the overused Principal Component Analysis (PCA). Although...
Dealing with Varying Results in PAH Quantification
There is an old adage, often referred to as Segal’s Law, that states: “A man with one watch knows what time it is, a man with two is never sure”. I use this a lot for my work when I am presenting. I am often given data where samples get sent to two different laboratories for the same analyses. It is usually done to...
Make sure your investigation has legal chain of custody
It is arson awareness and here is our third blog for arson investigators. One of the most important parts of a successful arson investigation and potential conviction (other than having video or photographic evidence of the arsonist) is the collection of samples and identifying the presence of an ignitable liquid...
Don’t let matrix get in your way
We recently discussed the issue of matrix and how the other stuff in your fire debris sample can be problematic for the laboratory in identifying ignitable liquid residue in your evidence samples.