Gosh that Polish language scores graph is good. Clean bell curve, slight skew, classic little bump at 100 because the measure is truncated, and then this giant mess at 30 that looks more like something out of a heart rate monitor than a normal distribution.
Suspicious Discontinuities (2020)
51–60 of 109 posts
Re: Suspicious Discontinuities (2020)
#52Earlier quoted context omitted.
I think because the gradient is simply too confusing for laypeople to understand. Even for a simple system like US social security that has a gradient. For every $2 you make over the limit, you lose $1 in benefits. I've heard countless times misconceptions of people thinking they'd be losing money (as in literally having less money net) by working.
This does happen in Finnish tax system. Your tax rate (percent with one decimal) is calculated based on your annual gross income. Rates are supposed to be calculated smoothly, and they are certainly calculated for each individual separately. In reality they are step functions. It is surprisingly common to have people refuse promotions because if would put them above an income tax threshold, bump up their rate, and en…
I've encountered people talking about turning down a promotion to not "get above a tax bracket". They have invariably been wrong and just not understood the basic math, or done any research.
Lacking those basic skills might be a reason not to promote someone though, so perhaps it all works out for the best
Re: Suspicious Discontinuities (2020)
#53The marathon one has a simple - and fun - explanation: it’s great to run with people!
Many (most?) marathons have pace runners who run the course, hewing to each 30 minute and 15 minute finish. So there’ll be a 3:30:00 pacer, a 3:45:00 pacer and so on. Your local pacer might even have their pace on their shirt and may even have a flag so they’re super hard to miss as you’re running.
One friend of mine runs with a speaker, to play music and keep everyone’s spirits up.
By the end of the race they’d acquired a small army of marathoners! You could see their smiles for miles, and when they all finished together they had a huge party in the recovery area with the speaker :)
I’m surprised the marathon time discontinuity isn’t bigger :)
Re: Suspicious Discontinuities (2020)
#54Jim Roskind had a really nice talk [ https://www.youtube.com/watch?v=_uaaCiyJCFA ] at AWS Reinvent 2022 which highlighted the fence post problem. Basically, AWS was targeting P50 and P90 latencies in many services, and sure enough there were big clumps of latencies right under those target fence posts as engineers were basically gaming the metrics and nerfing the >P90 latencies to make it happen.
I don't think that counts as gaming the metric. It's an example of a metric that even when targeted in good faith results in consequences management didn't intend.
Re: Suspicious Discontinuities (2020)
#55Indian laws have the same too. For taxation 'surcharge' applied to high income groups, a patchwork called "marginal relief" fixes it [1], however, leaves ranges in income where 100% of incremental income goes away in taxes. [1] https://cleartax.in/s/marginal-relief-surcharge Another place where thresholding is misplaced is minors (below the age of 18 years) being subject to different laws (this is for India at least)…
Why cant they just scan the minor's texts/calls, send them to therapy and rehabillitation and RICO the fuck out of their "superiors"?
Re: Suspicious Discontinuities (2020)
#56Indian laws have the same too. For taxation 'surcharge' applied to high income groups, a patchwork called "marginal relief" fixes it [1], however, leaves ranges in income where 100% of incremental income goes away in taxes. [1] https://cleartax.in/s/marginal-relief-surcharge Another place where thresholding is misplaced is minors (below the age of 18 years) being subject to different laws (this is for India at least)…
Why cant they just scan the minor's texts/calls, send them to therapy and rehabillitation and RICO the fuck out of their "superiors"?
I am not sure. What I have heard is that the minor pleads guilty for the entire crime (possibly in exchange for some money behind the scenes).
The broader point is that being a couple days or months younger or older than eighteen years should not result in a drastically different outcomes to begin with.
Re: Suspicious Discontinuities (2020)
#57Would test score problem be solved if teachers graded individual questions, not entire test?
it depends what the purpose of grading is. if the people is to purely assess, grading question by question is better. if the purpose is to provide feedback, knowing how the student did in general can substantially help with identifying what to emphasize
Re: Suspicious Discontinuities (2020)
#58Gosh that Polish language scores graph is good. Clean bell curve, slight skew, classic little bump at 100 because the measure is truncated, and then this giant mess at 30 that looks more like something out of a heart rate monitor than a normal distribution.
> this giant mess at 30 that looks more like something out of a heart rate monitor than a normal distribution.
Right, it's as if someone shot the heart with a defibrillator - because that's a good analogy of what is actually happening, given the "arbitrary negative effects for people" failing the exam are basically determining the course of one's future (or at least feel like this to the people and their parents at the time).
In particular, having passed "matura" is the lowest level kind of threshold used (both formally and informally) by employers considering job applicants; much like some higher-skill jobs still require a specific university degree, not having "matura" will cut you out of a large chunk of low-skill and entry-level jobs.
Couple failed "matura" with any kind of criminal record - and the two, I imagine, are probably correlated - and you can be screwed for life, economically speaking. It is a big deal, and teachers know it.
IDK what the current system is, but for my cohort, it was possible to repeat the exam in subsequent years - but like with any kind of degree, chances of someone doing that drop sharply with temporal distance; at some point, people just find a path for their lives and are more interested in present-day challenges than going back to finish some degree.
Re: Suspicious Discontinuities (2020)
#59Earlier quoted context omitted.
Same in slovenia for eg. kindergarten prices, 1eur over the line, 90eur more per month in fees.
I remember when my grandfather died, and my grandmother got part of his pension. It put her pension above a max threshold for old age / low pension (cheaper phone bill, no tv taxes, ...) by, ... hold your hats... 2 Euro. Father called the service ... "sorry, we can not do anything about that". She lost over 100 Euro in benefits because technically... she was not low pension anymore but was financially WAY more poor t…
> Sometimes, those lines really screw people over.
Another angle is how they affect the living. Plenty of young adults delay moving out from their parents, or starting a career, because changes in combined household income would cross one of those magic threshold, and ending up screwing the parents and younger siblings for life.
Such delaying may not be as immediately critical to the person, but it alters the course of their lives in significant ways.
Re: Suspicious Discontinuities (2020)
#60Earlier quoted context omitted.
If you grade individual questions, you don't know the total score.
The incentive to find the extra point would partially disappear.
Unfortunately this is the final exam from pre-university education. You can think of it as one's first educational degree, a step below bachelor's. It's expected - particularly by employers - that everyone should achieve it.