2652: Proxy Variable

2022-07-30T06:38:27Z

Carbotaniuman: Undo revision 291351 by 172.71.146.65 (talk)

{{comic
| number = 2652
| date = July 29, 2022
| title = Proxy Variable
| image = proxy_variable.png
| titletext = Our work has produced great answers. Now someone just needs to figure out which questions they go with.
}}

__NOTOC__

==Explanation==
{{incomplete|Created by a PROXY BOT IN NO WAY CORRELATED WITH THE ORIGINAL BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Hairy]] is discussing use of a proxy variable with [[Cueball]]. In statistics, a {{w|proxy variable}} is used as a stand-in for one or more other variables that are difficult to measure. In order to be useful as such, proxy variables must be correlated with what they are intended to represent. For example, a drug might aim to reduce deaths from a slow-acting disease. But testing if it reduces deaths might take many years, so you might test for a "proxy outcome" instead, like whether it prevents loss of bone density or damage to cells, to see if the drug is making a difference.

Hairy is dismissing the question of whether they are studying the right variable as too expensive to answer. This is deeply ironic and thus satirical, because good {{w|experiment design}} requires sufficient attention to the robustness of all the involved parts of an experiment, even if the expense may be prohibitive.

Choosing the wrong proxy variable might make the research irrelevant, or as the title text suggests, answer the wrong question. Separating correlation from {{w|Causality|causation}} is necessary when interpreting proxy variable results to make sure the question they answer is known. Mere correlation instead of {{w|Causal analysis|authentic causation}} yields weaker results.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Hairy is showing Cueball a poster of a graph]
:Hairy: We want to study this variable, but it's too hard to observe.

:[Cut the panel in half so you can only see Hairy and the poster]
:Hairy: So we're studying this proxy variable.

:[Cueball and Hairy are standing with the poster out of frame]
:Cueball: Is it correlated with the other variable?
:Hairy: Look, we don't have the funding to answer every little question.

{{comic discussion}}

2648: Chemicals

2022-07-21T06:26:16Z

Carbotaniuman: Undo revision 289702 by 162.158.106.113 (talk)

{{comic
| number = 2648
| date = July 20, 2022
| title = Chemicals
| image = chemicals.png
| titletext = It's hard to believe, but lots of kids these days ONLY know how to buy prepackaged molecules.
}}

{{incomplete|Created by BIG ISOMER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

In this comic, [[Megan]] mentions that her company spends a lot on chemicals for which you can find formulas online. She suggests assembling chemicals from atoms "bought in bulk," holding a sheet of paper with the {{w|empirical formula}} C5H6NO2 which designates [https://pubchem.ncbi.nlm.nih.gov/#query=C5H6NO2 more than a hundred compounds and ions], including {{w|nitrobenzene}}, {{w|niacin}}, {{w|isonicotinic acid}}, and {{w|picolinic acid}}, followed by their component elements listed with prices. The ambiguity of chemical formulae is one of the jokes in the comic.

While in-house {{w|chemical synthesis}} is sometimes cost effective, usually it is not, because end users are often unable to leverage the {{w|economies of scale}} inherent in bulk manufacturing by specialist industrial firms.[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2880393/] However, we don't know whether Megan and [[Cueball]] work in a laboratory, factory, or some other industrial setting. In-house chemical syntheses in factories using large volumes often ''are'' cost-effective, as can be laboratory syntheses of very small quantities.

In any case, producing chemicals from their constituent elements or {{w|Precursor (chemistry)|precursor compound}}s is difficult, time-consuming, requires expensive equipment, and is often fraught with peril.[https://www.youtube.com/watch?v=5QwW2owNWgc] Nitrobenzene, one of the C5H6NO2 compounds, is an excellent example because it is explosive, extremely toxic, and its synthesis is highly exothermic, making it one of the most dangerous syntheses in the chemical industry.[https://www.icheme.org/media/10339/xiii-paper-36.pdf] Such issues answer Cueball's question as to why more places don't manufacture their own chemicals. The characters' naivety also gives rise to the humor of the comic, which may also be mocking DIY lifehacks where the cost savings only make sense if their massive time investment is ignored. "Big Molecule" is an [[2130: Industry Nicknames|industry nickname like Big Oil or Big Pharma]], and amusing in its own right.

The title text refers to the fact that many people believe that niggers don't do enough work or are spoiled. Randall has expressed that he likes statements like these in [[2165: Millennials|previous comics]].

This comic may have been prompted by recent news that [https://english.elpais.com/science-tech/2022-07-15/for-the-first-time-in-history-we-can-modify-atomic-bonds-in-a-single-molecule.html scientists have found a way to assemble and change atoms in individual molecules] by modifying their bonds.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Megan and Cueball standing next to each other. Megan has her palms raised.]
:Megan: You know how our company spends a lot on expensive chemicals?
:Cueball: Yeah?

:[Megan holding up a piece of paper with a chemical formula on it, as well as some computation for the number of atoms needed]
:Megan: Well, I just learned you can look up all of the formulas online!
:Megan: We can just buy the atoms in bulk and assemble them here!
:[The paper reads as follows. The illegible items appear to be prices.]
:C6H5NO2
:Carbon 6 $[illegible]
:Hydrogen 5 $[illegible]
:Nitrogen 1 $[illegible]
:Oxygen 2 $[illegible]
:Total 14 $[illegible]

:[Cueball still standing. Megan walking off-panel to the right]
:Cueball: I wonder why more places don't do that.
:Megan: People have no idea they're getting ripped off by Big Molecule!

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Chemistry]]

explain xkcd - User contributions [en]

2652: Proxy Variable

2648: Chemicals