Week 40 - Accuracy

I was going to name this week, "Disrespect", but I started thinking that my discussion on accuracy vs. precision would bring home the point adequately. This week was the last in our series of quality assurance sessions taught in the county for 4-H/FFA youth who are taking market animals to the county fair. This session became necessary when people thought that animals could be treated any way they damn well pleased, and they lacked respect and forethought on the well-being of the animals they were showing. Yet, these were the same folks who were talking in the back of our jam-packed session, looking at each others' TFLNs and pictures on their phones. Their disrespect for our volunteer efforts.to educate youth about proper animal care and health was dismaying.

Accuracy vs. Precision (credit NOAA.com)

Now let's talk about a work example of my topic of the week. As we work towards better hydrogen measurement, we greatly struggle with the fact that any errors can lead to loss of hydrogen in the sample data. However, we don't know what we're losing, so we have to standardize the measurement to recovery curves and figure out the loss, and then look at our consistency in measurement. Unfortunately, our precision thus far overrides our ability to confirm accurate measurements. I think that the following image from the National Oceanic and Atmospheric Administration bicentennial celebration site adequately diagrams what I'm trying to say. Precision is merely grouping, but accuracy is getting data that is truly exemplary of the result. For example, you can see from the following picture of protozoa (taken from a day in the lab) that there are a ton of protozoa gathered around a food source. Hypothetically, if I'm doing a counting 50 grids across a counting chamber, and I see this and count all of these guys... they can greatly skew my accuracy. Am I precise in my measurement? Absolutely. But, I am not actually accurate in my estimation of the true mean. However, if I randomly land on this grouping in a preset counting pattern (which is what we do), then I can't know if there aren't other groups like this, and so we accept that it doesn't not skew our estimation any more than any other occurrence.

Crowd of protozoa around food source.

So back to my teaching example with the disrespectful teenager. Teaching to a group, I'm aiming for a certain accuracy in what I teach, and my opinion is that some kids are just going to miss the mark because they don't care about others, or learning proper animal care. These kids are lost and shouldn't be allowed to interfere with my ability to teach the rest of the group. Could I discipline them and force them to pay attention. Yeah, sure. But can I force them to learn? No. And thus, because I care more about learning than the perception of attention, I give up a little bit of precision in the results from my teaching efforts (that, and apparently, I can't kick them out of the session for no credit - that would be ideal). But, by maintaining my cool and controlling their impact on others, I can lose some precision but will not lose the accuracy of my efforts in education the general youth population about animal care.

Homebrew hard cider helps with the thinking.

Betsy eating melon.

In the home life, baby continues to grow happily and Betsy continues to cause trouble. Betsy has now been taught how to eat melon off the rind instead of eating the entire rind and then mercilessly depositing chunks everywhere in her path of chaos - either by digestion or lack thereof. It's nice that's she's become so civilized, but keeping a dog around that requires someone's hands to hold her melon while she eats it is a little time consuming. Same as humans - civilization takes too much effort. Why did we train her to do this??? I often wonder what kind of a big sister pup Betsy will become. I think it will probably evolve over time from the over-protective guardian to the one trying to prevent accidents, to the willing scapegoat, and finally as a reluctant old trouble-maker in her late life. Of course, only time will tell, but with the weather perking up and that porch swing calling my name - I spend a bit more time engulfed in thought than before. For what it's worth - I like sitting on that porch swing. Hope to do a whole lot more of it this summer.