• plandeka@lemmy.world
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          6 months ago

          It’s absolutely not. Median is a value in the middle of a sorted set and average is, well, average. In the set of 1, 7, 10: 7 is median and 6 is average.

          • lseif@sopuli.xyz
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            6 months ago

            as @force pointed out, ‘average’ has many meanings (haha). of course a lot of the time, average is used as ‘mean’. but…not always!

          • force@lemmy.world
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            6 months ago

            Idk man looking up a definition for “average” is like

            1. a number expressing the central or typical value in a set of data, in particular the mode, median, or (most commonly) the mean, which is calculated by dividing the sum of the values in the set by their number.

            and

            1. Any measure of central tendency, especially any mean, the median, or the mode. [from c. 1735]

            and

            1 a : a single value (such as a mean, mode, or median) that summarizes or represents the general significance of a set of unequal values

            doesn’t look like that dude’s using the word “wrong” to me, a lotta people and mathematicians definitely recall using “average” meaning median

          • Tabula_stercore@lemmy.world
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            6 months ago

            Such irony that this comment gets downvoted on a meme about failing education

            Even with a simple, yet very clear example

            • efstajas@lemmy.world
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              6 months ago

              What’s ironic here is your comment, lol. “Average” can and is absolutely used to say mean or median or any other average that is representative based on the dataset in question. When you ask a statistician to calculate an average of a dataset they probably won’t just go calculate the mean, they’ll think about which value is most appropriate in context.

          • Resonosity@lemmy.world
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            6 months ago

            I agree with this. In my stats class in college, we never conflated average and median. They meant two different things.

          • lugal@sopuli.xyz
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            6 months ago

            No, it wasn’t wrong because it didn’t specify which average was meant. If it was “arithmetic average”, it would be wrong.

            • Lemmeenym@lemm.ee
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              6 months ago

              It would still be right. The test results are reported on a normalized curve so all measures of central tendency are all equal.

              • lugal@sopuli.xyz
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                6 months ago

                “I have a ball”
                “So you have a red ball?”
                “No, it’s green”
                “If you don’t specify then the statement needs to hold for all balls to be correct.”

                And by the way: for the given plot, it is correct for all averages

                • Kazumara@discuss.tchncs.de
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                  6 months ago

                  More like

                  “Balls are orange”
                  “That’s wrong”
                  “Ah but basketballs are balls and they are orange, gotcha”
                  “No, you just said balls, that’s too generic, if you meant basket balls you should have said basket balls.”

      • Deebster@lemmy.ml
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        6 months ago

        Ackchyually, they never said which average they meant, you just assumed mean.

      • Aceticon@lemmy.world
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        6 months ago

        True, but those who know what “median” means probably also know what a “quartile” means, so if I used “median” it would’ve made my comment less of an “obvious, duh!” thing and spoil the unstated point I’m making as well as the joke.

        Best leave the mathematical incorrectness there to preserve the feeling of obviousness.

        • Karyoplasma@discuss.tchncs.de
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          6 months ago

          Yes. In a normal, or Gaussian, distribution, the data is symmetrically distributed around the mean and thus mean (average value), mode (most frequent value) and median (middle value) all fall on the same point, which is the highest point of the curve.

        • UnderpantsWeevil@lemmy.world
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          6 months ago

          Consider an exam in which there are two questions: one very easy and one very hard. You’ll get a supermajority of people who answer the first question and two tiny tails - zero correct, two correct - such that the mode is very high and the outlayer groups are very small.

          Then well over half the people are in the median and mean.

      • Flying Squid@lemmy.world
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        6 months ago

        Only all the children in Lake Wobegon are above average. It’s balanced out by them all turning into idiots when they become adults.

    • doingthestuff@lemmy.world
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      6 months ago

      Everyone should be in the top! Everyone should have unlimited resources from disabled addicts to military bioweapons developers - it should be a flat line, a plateau!

      • CaptnNMorgan@reddthat.com
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        6 months ago

        Bioweapon developers should be shot in the street. Disabled addicts should be provided the proper help they need; and the education should be changed so there are less disabled addicts and bioweapon developers alike.

  • son_named_bort@lemmy.world
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    6 months ago

    I was skeptical of these numbers until I did the research. It’s even worse than I thought. Did you know that only 20% of students test in the top quintile? Is our children learning?

    • UnderpantsWeevil@lemmy.world
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      6 months ago

      One could construct tests where this isn’t a given. Create an exam with one really easy question and one really hard question. You’ll end up with a huge spike in the center and two tiny tails. The top quintile of correct answers (<=1.6 correct answers) will be vanishingly small.

  • niktemadur@lemmy.world
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    6 months ago

    I can almost see a facebook post along the lines of:
    One doesn’t have to be a rocket scientist to understand how terrible things are, when fully 25% of the population are in the bottom quartile.

    • IvanOverdrive@lemm.ee
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      6 months ago

      25%!? That’s nothing. Half of people are below average. That’s twice of what you quoted!

    • MJKee9@lemmy.world
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      6 months ago

      My state’a standardized test says kids are “at risk” if they aren’t in the top 40% of the test. The top 50% could all be traditional “a-b” students. But because they weren’t in the top 80% of a-b students they are at risk for failing academically… It’s so asinine and disheartening. The last half of the year is devoted to this idiotic test. Kids could be learning stuff that will enrich themselves… Instead they are learnig how to take a test better.

  • Nobody@lemmy.world
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    6 months ago

    I’m surprised it’s only 25%. These days, I’d figure at least 40% would be in the lowest quartile. Has anyone checked the math on this?

  • JackGreenEarth@lemm.ee
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    6 months ago

    An education system that always fails a set number of people, regarless of how well people do, is a bad system, however.

    • Nougat@fedia.io
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      6 months ago

      There will always be 25% in the bottom quartile, regardless of how well any students perform.

      • Poplar?@lemmy.worldOP
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        6 months ago

        I think their point is that you could have people in the bottom quartile who learned what they are expected to, are capable, but are failed anyway because of how they compare to others.

        (Assuming curved tests really work like that, never bothered reading the pretty long grading policies)

        • Nougat@fedia.io
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          6 months ago

          Nothing about the post says anything about how many students passed or failed. Just that the lowest 25% are the lowest 25%.

          Yes, A = A.

          • Poplar?@lemmy.worldOP
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            6 months ago

            I did post it as a joke. Note how I started my comment with “I think their point is”, that isn’t my view :)

            There’s also difference between pretending to miss for a joke that dividing things into quartiles necessarily means a bottom 25% exists (what the meme does). And noting that it’s weird failing people based on how they do compared to others and not if they actually actually learn (me suggesting what the user JackGreenEarth was probably trying to get at).

    • InquisitiveApathy@lemm.ee
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      As Nougat said, this has nothing to do with passing or failing and is just a consequence of measuring performance. If 100 people take a test and the lowest 25 scorers all have a 95 out of 100 points then they are still in the bottom quartile regardless of the fact that every single student passed with flying colors.

      Showing a bell curve with no context means nothing.

    • PrinceWith999Enemies@lemmy.world
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      6 months ago

      I’ve been graded on a curve, and I’ve done it myself a couple of times. IMO, it’s usually a sign of a bad class (too much material being crammed in) or a bad teacher (didn’t get the concepts across to the majority of the students).

      That said, it’s usually done when it’s needed to prevent a significant portion of the class from failing. I remember a chem exam I took where a 16/100 was a C.

      The basic idea is that grades are normally distributed (ie a bell curve) which allows you to find the average grade range and shift the letter grade (eg a C or C+). There’s some professors who take the idea too far and rather than working off of an actual normal distribution try to fit the procedure to a simply skewed distribution or use it to pull down an 85/100 to a C, but in my experience that’s the exception to the rule, especially in math/science courses.

      Also, iirc this is a parody account.

      • scoobford@lemmy.zip
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        6 months ago

        I agree. My calc I professor would just silently scribble equations on the board, then turn around, gesture wildly, and shout “You see”.

        I remember right before the drop date, I had a 34 in the class, and he took time out of class to beg us to study because if too many people failed, he might have consequences.

        The only grade left was the final. I did much worse on it than the rest of the course, but my course grade shot up to the low 70s. Sure enough, I had the like 4th highest grade in the class.

        • PrinceWith999Enemies@lemmy.world
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          6 months ago

          You’re right, but it depends on how you want to think about it. They’re not necessarily graded on a curve, but with standardized tests you usually have both a history and a design target. They’re intended to produce (for example) a normal curve with a specific mean (eg mean IQ = 100) and they’ll adjust the test year over year to keep within those bounds. In other words, the grades don’t change but the test does.

          Curves exist because failing 90% of your class is a really bad look.

          • Nougat@fedia.io
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            6 months ago

            Oh I’m not saying standardized tests are perfect by any means. Plenty of flaws.

  • Margot Robbie@lemmy.world
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    6 months ago

    But then again, 25 percent of American students are also in the top quartile on standardized tests, so it evens out.

    • mPony@lemmy.world
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      6 months ago

      People understand “glass half empty / glass half full”, but they can’t quite grasp a bell curve

  • CluckN@lemmy.world
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    6 months ago

    Nice try everyone knows that the soyjack is on one end and the chad is at the other.