Re: OT: London Cops seem to have a $54K time problem

Discussion in 'Digital Photography' started by Pete A, Jan 21, 2012.

  1. Pete A

    Pete A Guest

    On 2012-01-21 19:59:10 +0000, Richard said:

    > Chris Malcolm wrote:
    >> In rec.photo.digital Pete A wrote:
    >>
    >>> President Eisenhower expressed shock when he heard that half of all
    >>> Americans are of below-average intelligence.

    >>
    >> I forget which newly appointed British Minister for Education reported
    >> the distressing fact that half of Britain's schoolchildren were below
    >> average in reading and arithmetic and promised to do something about
    >> it.

    >
    > You made that up, didn't you?



    How about these quotes:

    "Schools with below average test results will be either be [sic] placed
    in the special measures category or given notice to improve."

    "And 1,486 state secondaries – 48.6 per cent – were below average on
    the main five A* to C GCSE measure, including English and maths."

    source:
    <http://www.dailymail.co.uk/news/article-2002395/More-5-000-schools-face-special-measures-Ofsted-crackdown.html>
    Pete A, Jan 21, 2012
    #1
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  2. Pete A

    tony cooper Guest

    On Sun, 22 Jan 2012 09:39:38 -0500, Alan Browne
    <> wrote:

    >On 2012-01-21 19:34 , Pete A wrote:
    >> On 2012-01-21 21:30:50 +0000, Alan Browne said:
    >>
    >>> On 2012-01-21 15:37 , Pete A wrote:
    >>>> [...]
    >>>> How about these quotes:
    >>>>
    >>>> "Schools with below average test results will be either be [sic] placed
    >>>> in the special measures category or given notice to improve."
    >>>
    >>> Nothing wrong with that. A given school, with say 500 students, is a
    >>> statistically relevant sample. It's average should be close to the
    >>> national average for the same curriculum.

    >>
    >> Yes, one would hope so.
    >>
    >>>> "And 1,486 state secondaries - 48.6 per cent - were below average on the
    >>>> main five A* to C GCSE measure, including English and maths."
    >>>
    >>> As above.

    >>
    >> Both quotes show total failure to understand basic statistics: if half
    >> of the schools are average or above then the other half, by definition,
    >> must be below average. The figure of 48.6% being below average is so
    >> close to 50% that this simple logic should've been obvious to the writer.
    >>
    >> It's impossible to have all schools performing average or above although
    >> this is what parents expect. Nobody wants their children to attend a
    >> below average school.

    >
    >This is where you're wrong. It's impossible for all students to be
    >above average.


    "Impossible" was not a word chosen wisely. In this area, there are
    magnet schools for the gifted. I would imagine that all of the
    students in a school such as this would be above-average in
    intelligence for their age group.

    However, you may be thinking of a ranking of the students that attend
    a specific school. Even in a school for the gifted, an average level
    of intelligence can be determined and half will be above and half
    below that level. The ones below might still be above-above average
    compared to the general population of students in their age group.

    There are also, by the way, schools in this area for students who do
    not do well in the regular system. The students at these schools are
    not necessarily less intelligent on average than the students in the
    general population in their age group. Their inability to perform in
    the regular system may be because of social and behavior issues and
    not native intelligence.

    I understand that intelligence does not progress as knowledge is
    acquired as "age group" might indicate. It's just that comparisons of
    intelligence among students is generally by age group.
    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 22, 2012
    #2
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  3. Pete A

    PeterN Guest

    On 1/22/2012 12:03 PM, Alan Browne wrote:
    > On 2012-01-22 11:26 , tony cooper wrote:
    >> "Impossible" was not a word chosen wisely. In this area, there are
    >> magnet schools for the gifted. I would imagine that all of the
    >> students in a school such as this would be above-average in
    >> intelligence for their age group.

    >
    > Correct. However the context of the statement (that Pete supplied) is in
    > the general school system.
    >
    > Quibble: it's not about 'intelligence' but performance and test results.
    >


    My quibble:

    Assume a student population of 100.
    The grade points are;
    75 A
    25 c

    Obviously more than half the students will be above average.

    --
    Peter
    PeterN, Jan 22, 2012
    #3
  4. Pete A

    tony cooper Guest

    On Sun, 22 Jan 2012 12:03:38 -0500, Alan Browne
    <> wrote:

    >On 2012-01-22 11:26 , tony cooper wrote:
    >> "Impossible" was not a word chosen wisely. In this area, there are
    >> magnet schools for the gifted. I would imagine that all of the
    >> students in a school such as this would be above-average in
    >> intelligence for their age group.

    >
    >Correct. However the context of the statement (that Pete supplied) is
    >in the general school system.
    >
    >Quibble: it's not about 'intelligence' but performance and test results.


    I wouldn't say that the more intelligent necessarily always perform or
    test better, but I think there's enough correlation there for a
    generalization. I think we've all known people who are very
    intelligent who don't perform or test well, and people who are not
    that bright who do very well by perseverance.

    In a school for the gifted, though, there's a much stronger
    correlation because they are in this school based on past performance
    or testing.

    Still, there's a bottom to every class.
    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 22, 2012
    #4
  5. Pete A

    tony cooper Guest

    On Sun, 22 Jan 2012 12:28:35 -0500, PeterN
    <> wrote:

    >On 1/22/2012 12:03 PM, Alan Browne wrote:
    >> On 2012-01-22 11:26 , tony cooper wrote:
    >>> "Impossible" was not a word chosen wisely. In this area, there are
    >>> magnet schools for the gifted. I would imagine that all of the
    >>> students in a school such as this would be above-average in
    >>> intelligence for their age group.

    >>
    >> Correct. However the context of the statement (that Pete supplied) is in
    >> the general school system.
    >>
    >> Quibble: it's not about 'intelligence' but performance and test results.
    >>

    >
    >My quibble:
    >
    >Assume a student population of 100.
    >The grade points are;
    >75 A
    >25 c
    >
    >Obviously more than half the students will be above average.


    With a skew like that, I'd challenge the validity of the testing
    format.

    For the past several years I've worked (very) part-time grading
    standard achievement school tests. The company grades tests for
    several states and for all grades from third to twelfth.

    When a particular question turns up a skew like that - or the reverse
    of that - the question is removed from the results. The school
    systems want questions that return more right answers than wrong, but
    not really a bell curve. A lop-sided bell, perhaps, that shows the
    schools are doing well in teaching, but not a curve that says the
    questions are too easy.

    The questions, by the way, that result with a preponderance of
    incorrect answers are usually badly or ambiguously phrased. It's not
    that the students don't understand the problem; they don't understand
    the question as written.


    --
    Tony Cooper - Orlando, Florida
    tony cooper, Jan 22, 2012
    #5
  6. Pete A

    PeterN Guest

    On 1/22/2012 1:41 PM, Savageduck wrote:
    > On 2012-01-22 09:28:35 -0800, PeterN <> said:
    >
    >> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>> magnet schools for the gifted. I would imagine that all of the
    >>>> students in a school such as this would be above-average in
    >>>> intelligence for their age group.
    >>>
    >>> Correct. However the context of the statement (that Pete supplied) is in
    >>> the general school system.
    >>>
    >>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>

    >>
    >> My quibble:
    >>
    >> Assume a student population of 100.
    >> The grade points are;
    >> 75 A
    >> 25 c
    >>
    >> Obviously more than half the students will be above average.

    >
    > ....er, not quite.
    > What is above average at THAT SCHOOL?
    > In your example using Grades of A & C, you have omitted an intermediary
    > grade point of "B", even if no students scored "B's". In calculating a
    > skewed mean for that particular test for that particular population you
    > will have mean test/exam scores which fall 2/3 of the way into the "B"
    > criteria. Therefore exactly the same number of students at that school
    > will be above average and below average. However the skewed mean scores
    > will be skewed 33.3% towards the high score.


    Which of the students who scored an "A" will be below the average?


    >
    > Average in any given group is still average, but once you get into
    > statistics things might not be what you believe they should be.
    > < http://en.wikipedia.org/wiki/Skewness >
    > <
    > http://www.ma.utexas.edu/users/mks/statmistakes/skeweddistributions.html >
    > < http://en.wikipedia.org/wiki/Mean >
    >
    > Now if you compare that school's scores with other schools being tested
    > with the same standardized test/exam, then calculated the average for
    > all of those schools, you might come to a different conclusion.
    >

    Proving my point that using "average" as a criteria is not always
    logical. In the skew example I gave the problem is how to help those at
    the bottom so that the skew will be eliminated, without moving the top
    to the left.

    --
    Peter
    PeterN, Jan 22, 2012
    #6
  7. Pete A

    Ray Fischer Guest

    PeterN <> wrote:
    >On 1/22/2012 12:03 PM, Alan Browne wrote:
    >> On 2012-01-22 11:26 , tony cooper wrote:
    >>> "Impossible" was not a word chosen wisely. In this area, there are
    >>> magnet schools for the gifted. I would imagine that all of the
    >>> students in a school such as this would be above-average in
    >>> intelligence for their age group.

    >>
    >> Correct. However the context of the statement (that Pete supplied) is in
    >> the general school system.
    >>
    >> Quibble: it's not about 'intelligence' but performance and test results.

    >
    >My quibble:
    >
    >Assume a student population of 100.
    >The grade points are;
    >75 A
    >25 c
    >
    >Obviously more than half the students will be above average.


    Nope. The average is an A. No students are above average and
    many are below average.

    The math:
    A = 4
    C = 2
    (75 * 4) + (25 * 2) = 350
    350 / 100 = 3.5 = A (rounded to the nearest letter grade)

    --
    Ray Fischer | None are more hopelessly enslaved than those who falsely believe they are free.
    | Goethe
    Ray Fischer, Jan 22, 2012
    #7
  8. Pete A

    PeterN Guest

    On 1/22/2012 4:06 PM, Ray Fischer wrote:
    > PeterN<> wrote:
    >> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>> magnet schools for the gifted. I would imagine that all of the
    >>>> students in a school such as this would be above-average in
    >>>> intelligence for their age group.
    >>>
    >>> Correct. However the context of the statement (that Pete supplied) is in
    >>> the general school system.
    >>>
    >>> Quibble: it's not about 'intelligence' but performance and test results.

    >>
    >> My quibble:
    >>
    >> Assume a student population of 100.
    >> The grade points are;
    >> 75 A
    >> 25 c
    >>
    >> Obviously more than half the students will be above average.

    >
    > Nope. The average is an A. No students are above average and
    > many are below average.
    >
    > The math:
    > A = 4
    > C = 2
    > (75 * 4) + (25 * 2) = 350
    > 350 / 100 = 3.5 = A (rounded to the nearest letter grade)
    >


    You didn't account for compensation for skewed curves. See the Duck's
    citations.

    --
    Peter
    PeterN, Jan 22, 2012
    #8
  9. Pete A

    Ray Fischer Guest

    PeterN <> wrote:
    >On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >> PeterN<> wrote:
    >>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>> students in a school such as this would be above-average in
    >>>>> intelligence for their age group.
    >>>>
    >>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>> the general school system.
    >>>>
    >>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>
    >>> My quibble:
    >>>
    >>> Assume a student population of 100.
    >>> The grade points are;
    >>> 75 A
    >>> 25 c
    >>>
    >>> Obviously more than half the students will be above average.

    >>
    >> Nope. The average is an A. No students are above average and
    >> many are below average.
    >>
    >> The math:
    >> A = 4
    >> C = 2
    >> (75 * 4) + (25 * 2) = 350
    >> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)

    >
    >You didn't account for compensation for skewed curves.


    I was pointing out the fallacy of depending on rounded values.
    By definition, you cannot have more than half of the students
    score above average.

    --
    Ray Fischer | None are more hopelessly enslaved than those who falsely believe they are free.
    | Goethe
    Ray Fischer, Jan 22, 2012
    #9
  10. Pete A

    PeterN Guest

    On 1/22/2012 6:13 PM, Ray Fischer wrote:
    > PeterN<> wrote:
    >> On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >>> PeterN<> wrote:
    >>>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>>> students in a school such as this would be above-average in
    >>>>>> intelligence for their age group.
    >>>>>
    >>>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>>> the general school system.
    >>>>>
    >>>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>>
    >>>> My quibble:
    >>>>
    >>>> Assume a student population of 100.
    >>>> The grade points are;
    >>>> 75 A
    >>>> 25 c
    >>>>
    >>>> Obviously more than half the students will be above average.
    >>>
    >>> Nope. The average is an A. No students are above average and
    >>> many are below average.
    >>>
    >>> The math:
    >>> A = 4
    >>> C = 2
    >>> (75 * 4) + (25 * 2) = 350
    >>> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)

    >>
    >> You didn't account for compensation for skewed curves.

    >
    > I was pointing out the fallacy of depending on rounded values.
    > By definition, you cannot have more than half of the students
    > score above average.
    >


    Oh! <\end sarcastic tag>

    --
    Peter
    PeterN, Jan 23, 2012
    #10
  11. Pete A

    Ray Fischer Guest

    Eric Stevens <> wrote:
    >On 22 Jan 2012 23:13:43 GMT, (Ray Fischer) wrote:
    >
    >>PeterN <> wrote:
    >>>On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >>>> PeterN<> wrote:
    >>>>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>>>> students in a school such as this would be above-average in
    >>>>>>> intelligence for their age group.
    >>>>>>
    >>>>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>>>> the general school system.
    >>>>>>
    >>>>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>>>
    >>>>> My quibble:
    >>>>>
    >>>>> Assume a student population of 100.
    >>>>> The grade points are;
    >>>>> 75 A
    >>>>> 25 c
    >>>>>
    >>>>> Obviously more than half the students will be above average.
    >>>>
    >>>> Nope. The average is an A. No students are above average and
    >>>> many are below average.
    >>>>
    >>>> The math:
    >>>> A = 4
    >>>> C = 2
    >>>> (75 * 4) + (25 * 2) = 350
    >>>> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)
    >>>
    >>>You didn't account for compensation for skewed curves.

    >>
    >>I was pointing out the fallacy of depending on rounded values.
    >>By definition, you cannot have more than half of the students
    >>score above average.

    >
    >Umm - you can you know.
    >
    >52 52 52 53 53 55 59 52 52 25
    >
    >10 students with an average of 45.


    Your calculator is broken.

    --
    Ray Fischer | None are more hopelessly enslaved than those who falsely believe they are free.
    | Goethe
    Ray Fischer, Jan 23, 2012
    #11
  12. Pete A

    Ray Fischer Guest

    Eric Stevens <> wrote:
    >On 23 Jan 2012 07:29:07 GMT, (Ray Fischer) wrote:
    >
    >>Eric Stevens <> wrote:
    >>>On 22 Jan 2012 23:13:43 GMT, (Ray Fischer) wrote:
    >>>
    >>>>PeterN <> wrote:
    >>>>>On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >>>>>> PeterN<> wrote:
    >>>>>>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>>>>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>>>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>>>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>>>>>> students in a school such as this would be above-average in
    >>>>>>>>> intelligence for their age group.
    >>>>>>>>
    >>>>>>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>>>>>> the general school system.
    >>>>>>>>
    >>>>>>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>>>>>
    >>>>>>> My quibble:
    >>>>>>>
    >>>>>>> Assume a student population of 100.
    >>>>>>> The grade points are;
    >>>>>>> 75 A
    >>>>>>> 25 c
    >>>>>>>
    >>>>>>> Obviously more than half the students will be above average.
    >>>>>>
    >>>>>> Nope. The average is an A. No students are above average and
    >>>>>> many are below average.
    >>>>>>
    >>>>>> The math:
    >>>>>> A = 4
    >>>>>> C = 2
    >>>>>> (75 * 4) + (25 * 2) = 350
    >>>>>> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)
    >>>>>
    >>>>>You didn't account for compensation for skewed curves.
    >>>>
    >>>>I was pointing out the fallacy of depending on rounded values.
    >>>>By definition, you cannot have more than half of the students
    >>>>score above average.
    >>>
    >>>Umm - you can you know.
    >>>
    >>>52 52 52 53 53 55 59 52 52 25
    >>>
    >>>10 students with an average of 45.

    >>
    >>Your calculator is broken.

    >
    >I realised that was wrong after I posted.


    In more than one way.

    >I'm the last one with 25. Knock off 5 marks for my mistake and the


    You playing games by depending on rounding errors and too-small sample
    sizes.

    --
    Ray Fischer | None are more hopelessly enslaved than those who falsely believe they are free.
    | Goethe
    Ray Fischer, Jan 23, 2012
    #12
  13. Pete A

    PeterN Guest

    On 1/23/2012 2:10 PM, Ray Fischer wrote:
    > Eric Stevens<> wrote:
    >> On 23 Jan 2012 07:29:07 GMT, (Ray Fischer) wrote:
    >>
    >>> Eric Stevens<> wrote:
    >>>> On 22 Jan 2012 23:13:43 GMT, (Ray Fischer) wrote:
    >>>>
    >>>>> PeterN<> wrote:
    >>>>>> On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >>>>>>> PeterN<> wrote:
    >>>>>>>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>>>>>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>>>>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>>>>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>>>>>>> students in a school such as this would be above-average in
    >>>>>>>>>> intelligence for their age group.
    >>>>>>>>>
    >>>>>>>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>>>>>>> the general school system.
    >>>>>>>>>
    >>>>>>>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>>>>>>
    >>>>>>>> My quibble:
    >>>>>>>>
    >>>>>>>> Assume a student population of 100.
    >>>>>>>> The grade points are;
    >>>>>>>> 75 A
    >>>>>>>> 25 c
    >>>>>>>>
    >>>>>>>> Obviously more than half the students will be above average.
    >>>>>>>
    >>>>>>> Nope. The average is an A. No students are above average and
    >>>>>>> many are below average.
    >>>>>>>
    >>>>>>> The math:
    >>>>>>> A = 4
    >>>>>>> C = 2
    >>>>>>> (75 * 4) + (25 * 2) = 350
    >>>>>>> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)
    >>>>>>
    >>>>>> You didn't account for compensation for skewed curves.
    >>>>>
    >>>>> I was pointing out the fallacy of depending on rounded values.
    >>>>> By definition, you cannot have more than half of the students
    >>>>> score above average.
    >>>>
    >>>> Umm - you can you know.
    >>>>
    >>>> 52 52 52 53 53 55 59 52 52 25
    >>>>
    >>>> 10 students with an average of 45.
    >>>
    >>> Your calculator is broken.

    >>
    >> I realised that was wrong after I posted.

    >
    > In more than one way.
    >
    >> I'm the last one with 25. Knock off 5 marks for my mistake and the

    >
    > You playing games by depending on rounding errors and too-small sample
    > sizes.
    >



    In my original example, the sample size equaled 100% of the population.
    I posted it for reasons previously stated.

    --
    Peter
    PeterN, Jan 23, 2012
    #13
  14. Pete A

    Pete A Guest

    On 2012-01-23 19:10:28 +0000, Ray Fischer said:

    > Eric Stevens <> wrote:
    >> On 23 Jan 2012 07:29:07 GMT, (Ray Fischer) wrote:
    >>
    >>> Eric Stevens <> wrote:
    >>>> On 22 Jan 2012 23:13:43 GMT, (Ray Fischer) wrote:
    >>>>
    >>>>> PeterN <> wrote:
    >>>>>> On 1/22/2012 4:06 PM, Ray Fischer wrote:
    >>>>>>> PeterN<> wrote:
    >>>>>>>> On 1/22/2012 12:03 PM, Alan Browne wrote:
    >>>>>>>>> On 2012-01-22 11:26 , tony cooper wrote:
    >>>>>>>>>> "Impossible" was not a word chosen wisely. In this area, there are
    >>>>>>>>>> magnet schools for the gifted. I would imagine that all of the
    >>>>>>>>>> students in a school such as this would be above-average in
    >>>>>>>>>> intelligence for their age group.
    >>>>>>>>>
    >>>>>>>>> Correct. However the context of the statement (that Pete supplied) is in
    >>>>>>>>> the general school system.
    >>>>>>>>>
    >>>>>>>>> Quibble: it's not about 'intelligence' but performance and test results.
    >>>>>>>>
    >>>>>>>> My quibble:
    >>>>>>>>
    >>>>>>>> Assume a student population of 100.
    >>>>>>>> The grade points are;
    >>>>>>>> 75 A
    >>>>>>>> 25 c
    >>>>>>>>
    >>>>>>>> Obviously more than half the students will be above average.
    >>>>>>>
    >>>>>>> Nope. The average is an A. No students are above average and
    >>>>>>> many are below average.
    >>>>>>>
    >>>>>>> The math:
    >>>>>>> A = 4
    >>>>>>> C = 2
    >>>>>>> (75 * 4) + (25 * 2) = 350
    >>>>>>> 350 / 100 = 3.5 = A (rounded to the nearest letter grade)
    >>>>>>
    >>>>>> You didn't account for compensation for skewed curves.
    >>>>>
    >>>>> I was pointing out the fallacy of depending on rounded values.
    >>>>> By definition, you cannot have more than half of the students
    >>>>> score above average.
    >>>>
    >>>> Umm - you can you know.
    >>>>
    >>>> 52 52 52 53 53 55 59 52 52 25
    >>>>
    >>>> 10 students with an average of 45.
    >>>
    >>> Your calculator is broken.

    >>
    >> I realised that was wrong after I posted.

    >
    > In more than one way.
    >
    >> I'm the last one with 25. Knock off 5 marks for my mistake and the

    >
    > You playing games by depending on rounding errors and too-small sample
    > sizes.


    It's a completely valid dataset. It is the analysis of it that has lead
    to the false claim that it proves more than half of the students score
    above average.

    The "average" value of a dataset is a single number that most typifies
    the datapoints within it. Here's the dataset placed in order:

    25 52 52 52 52 52 53 53 53 59

    We can see by inspection that a suitable average is 52 or 53. Three
    commonly-used methods of calculating the average are:

    mean: 50.5
    median: 52
    mode: 52

    The arithmetic mean (aka mean) has been influenced heavily by the
    outlying datapoint of 25. An extreme example is:

    100000 52 52 52 52 52 53 53 53 59

    mean: 10048
    median: 52.5
    mode: 52

    This time, it's completely obvious that the mean of 10048 does _not_
    typify the values in the dataset :)

    The median is a far better average for data with high varience because
    it not only better typifies the dataset, it also prevents absurd
    conclusions being drawn such as "all but one of the values is far below
    average". The median is calculated such that no more than half of the
    samples can be above average and no more than half can be below.

    In the original dataset, with a median of 52, one data point is below
    average, 4 are average, and 4 are above average.

    In the second example, with a median of 52.5, half of the dataset is
    below average, the other half is above.

    The term "average" is often thought to imply only the arithmetic mean,
    but this is a misnomer.
    Pete A, Jan 23, 2012
    #14
  15. Pete A

    Bruce Guest

    Doug McDonald <> wrote:

    >On 1/26/2012 4:42 PM, Alan Browne wrote:
    >
    >>
    >>> My assertion that 50% of the schools will always score below average is
    >>> correct, regardless of the actual values.

    >>
    >> Don't let actual values get in the way, mighty inconvenient, wot.
    >>
    >>> If this is found not to be the
    >>> case in practice, then the scoring method is flawed...

    >>

    >
    >Actually it is wrong. Half the schools will score below the MEDIAN,
    >not the average.
    >
    >Doug Nitpicker



    Your nitpicking is misplaced because the term "average" can have more
    than one meaning, including the median, arithmetic mean and mode.

    http://en.wikipedia.org/wiki/Average
    Bruce, Jan 27, 2012
    #15
  16. Pete A

    Richard Guest

    Bruce wrote:
    > Doug McDonald <> wrote:
    >
    >> On 1/26/2012 4:42 PM, Alan Browne wrote:
    >>
    >>>
    >>>> My assertion that 50% of the schools will always score below
    >>>> average is correct, regardless of the actual values.
    >>>
    >>> Don't let actual values get in the way, mighty inconvenient, wot.
    >>>
    >>>> If this is found not to be the
    >>>> case in practice, then the scoring method is flawed...
    >>>

    >>
    >> Actually it is wrong. Half the schools will score below the MEDIAN,
    >> not the average.
    >>
    >> Doug Nitpicker

    >
    >
    > Your nitpicking is misplaced because the term "average" can have more
    > than one meaning, including the median, arithmetic mean and mode.
    >
    > http://en.wikipedia.org/wiki/Average


    Well, there ya go.
    Is Doug a below average nitpicker?
    ;)
    Richard, Jan 27, 2012
    #16
  17. Pete A

    Bruce Guest

    "Richard" <> wrote:
    >Bruce wrote:
    >> Doug McDonald <> wrote:
    >>
    >>> On 1/26/2012 4:42 PM, Alan Browne wrote:
    >>>
    >>>>
    >>>>> My assertion that 50% of the schools will always score below
    >>>>> average is correct, regardless of the actual values.
    >>>>
    >>>> Don't let actual values get in the way, mighty inconvenient, wot.
    >>>>
    >>>>> If this is found not to be the
    >>>>> case in practice, then the scoring method is flawed...
    >>>>
    >>>
    >>> Actually it is wrong. Half the schools will score below the MEDIAN,
    >>> not the average.
    >>>
    >>> Doug Nitpicker

    >>
    >>
    >> Your nitpicking is misplaced because the term "average" can have more
    >> than one meaning, including the median, arithmetic mean and mode.
    >>
    >> http://en.wikipedia.org/wiki/Average

    >
    >Well, there ya go.
    >Is Doug a below average nitpicker?
    >;)



    LOL!

    No, he's an intelligent guy whose contributions here are almost always
    worth reading. ;-)
    Bruce, Jan 27, 2012
    #17
  18. Eric Stevens <> writes:

    > On Fri, 27 Jan 2012 13:43:32 +0000, Bruce <>
    > wrote:
    >
    >>Doug McDonald <> wrote:
    >>
    >>>On 1/26/2012 4:42 PM, Alan Browne wrote:
    >>>
    >>>>
    >>>>> My assertion that 50% of the schools will always score below average is
    >>>>> correct, regardless of the actual values.
    >>>>
    >>>> Don't let actual values get in the way, mighty inconvenient, wot.
    >>>>
    >>>>> If this is found not to be the
    >>>>> case in practice, then the scoring method is flawed...
    >>>>
    >>>
    >>>Actually it is wrong. Half the schools will score below the MEDIAN,
    >>>not the average.
    >>>
    >>>Doug Nitpicker

    >>
    >>
    >>Your nitpicking is misplaced because the term "average" can have more
    >>than one meaning, including the median, arithmetic mean and mode.
    >>
    >>http://en.wikipedia.org/wiki/Average

    >
    > I wouldn't rely in Wikipedia for that. I have always been taught that
    > 'average' was the 'arithmetic mean' and that the other measurements of
    > central tendency were not the average.


    Whereas I have always been taught that "average" is a vague term meaning
    some indication of central tendency of a measurement, and that one of
    those three is normally what's meant. And that you should be more
    specific if appropriate.
    --
    David Dyer-Bennet, ; http://dd-b.net/
    Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
    Photos: http://dd-b.net/photography/gallery/
    Dragaera: http://dragaera.info
    David Dyer-Bennet, Jan 28, 2012
    #18
  19. Pete A

    nick c Guest

    Eric Stevens wrote:
    > On Fri, 27 Jan 2012 13:43:32 +0000, Bruce <>
    > wrote:
    >
    >> Doug McDonald <> wrote:
    >>
    >>> On 1/26/2012 4:42 PM, Alan Browne wrote:
    >>>
    >>>>> My assertion that 50% of the schools will always score below average is
    >>>>> correct, regardless of the actual values.
    >>>> Don't let actual values get in the way, mighty inconvenient, wot.
    >>>>
    >>>>> If this is found not to be the
    >>>>> case in practice, then the scoring method is flawed...
    >>> Actually it is wrong. Half the schools will score below the MEDIAN,
    >>> not the average.
    >>>
    >>> Doug Nitpicker

    >>
    >> Your nitpicking is misplaced because the term "average" can have more
    >> than one meaning, including the median, arithmetic mean and mode.
    >>
    >> http://en.wikipedia.org/wiki/Average

    >
    > I wouldn't rely in Wikipedia for that. I have always been taught that
    > 'average' was the 'arithmetic mean' and that the other measurements of
    > central tendency were not the average.
    >
    > Regards,
    >
    > Eric Stevens


    I share your opinion about Wikipedia.

    Oftentimes the median value of a series of numbers are viewed to mean
    it's the average value of a series of numbers. In reality average and
    median are not the same values.

    For example: When a series of numbers such as -

    13 10 20 19 and 15 are orderly rearranged to be 10 13 15 19 20 the
    Median value of those numbers is 15 (15 is just the middle number of a
    column of numbers) while the average value is 15.4 (the average value is
    derived by means of a mathematical computation of a column of numbers).

    It's easy to understand when the column consists of an odd number of
    values. When there is and even number of values in a column the two
    middle numbers become median values while the average value of a column
    of numbers remains a calculated single value number.

    It's the way of the West .... podner. :)
    nick c, Jan 28, 2012
    #19
  20. Pete A

    nick c Guest

    nick c wrote:
    > Eric Stevens wrote:
    >> On Fri, 27 Jan 2012 13:43:32 +0000, Bruce <>
    >> wrote:
    >>
    >>> Doug McDonald <> wrote:
    >>>
    >>>> On 1/26/2012 4:42 PM, Alan Browne wrote:
    >>>>
    >>>>>> My assertion that 50% of the schools will always score below
    >>>>>> average is
    >>>>>> correct, regardless of the actual values.
    >>>>> Don't let actual values get in the way, mighty inconvenient, wot.
    >>>>>
    >>>>>> If this is found not to be the
    >>>>>> case in practice, then the scoring method is flawed...
    >>>> Actually it is wrong. Half the schools will score below the MEDIAN,
    >>>> not the average.
    >>>>
    >>>> Doug Nitpicker
    >>>
    >>> Your nitpicking is misplaced because the term "average" can have more
    >>> than one meaning, including the median, arithmetic mean and mode.
    >>>
    >>> http://en.wikipedia.org/wiki/Average

    >>
    >> I wouldn't rely in Wikipedia for that. I have always been taught that
    >> 'average' was the 'arithmetic mean' and that the other measurements of
    >> central tendency were not the average.
    >>
    >> Regards,
    >>
    >> Eric Stevens

    >
    > I share your opinion about Wikipedia.
    >
    > Oftentimes the median value of a series of numbers are viewed to mean
    > it's the average value of a series of numbers. In reality average and
    > median are not the same values.
    >
    > For example: When a series of numbers such as -
    >
    > 13 10 20 19 and 15 are orderly rearranged to be 10 13 15 19 20 the
    > Median value of those numbers is 15 (15 is just the middle number of a
    > column of numbers) while the average value is 15.4 (the average value is
    > derived by means of a mathematical computation of a column of numbers).
    >
    > It's easy to understand when the column consists of an odd number of
    > values. When there is and even number of values in a column the two
    > middle numbers become median values while the average value of a column
    > of numbers remains a calculated single value number.
    >
    > It's the way of the West .... podner. :)
    >


    Ooops, additional clarification:

    When confronted with an even numbered column of numbers, the two middle
    numbers are Median values _that can be added together to obtain a single
    Median value number_ .

    Whew ......
    nick c, Jan 28, 2012
    #20
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