European Scholars: PISA Rankings Are “Utterly Wrong” and “Meaningless”
This from
Diane Ravitch:
Professor Svend Kreiner, a prominent statistician and psychometrician
at the University of Copenhagen in Denmark and Dr. Hugh Morrison of
Queens University in Belfast have published studies blasting the reliability and validity of the PISA league tables. They describe PISA’s rankings as “useless,” “utterly wrong,” and “meaningless.”
According to TES (London),
“Professor Svend Kreiner, a statistician from the University of
Copenhagen in Denmark, said that an inappropriate model is used to
calculate the Pisa rankings every three years. In a paper published this
summer, he challenges their reliability and shows how they fluctuate
significantly according to which test questions are used. He reveals
how, in the 2006 reading rankings, Canada could have been positioned
anywhere between second and 25th, Japan between eighth and 40th and the
UK between 14th and 30th.
“Dr Hugh Morrison, from Queens University Belfast in Northern
Ireland, goes further, saying that the model Pisa uses to calculate the
rankings is, on its own terms, “utterly wrong” because it contains a
“profound” conceptual error. For this reason, the mathematician claims,
“Pisa will never work”.
“The academics’ papers have serious implications for politicians,
including England’s education secretary Michael Gove, who justified his
sweeping reforms by stating that England “plummeted” down the Pisa
rankings between 2000 and 2009.
“The questions used for Pisa vary between countries and between
students participating in the same assessment. In Pisa 2006, for
example, half the students were not asked any reading questions but were
allocated “plausible” reading scores to help calculate their countries’
rankings.
“To work out these “plausible” values, Pisa uses the Rasch model, a
statistical way of “scaling” up the results it does have. But Professor
Kreiner says this model can only work if the questions that Pisa uses
are of the same level of difficulty for each of the participating
countries. He believes his research proves that this is not the case,
and therefore the comparisons that Pisa makes between countries are
“useless”.
“When the academic first raised the issue in 2011, the OECD countered
by suggesting that he had been able to find such wild fluctuations in
rankings only by deliberately selecting particular small groupings of
questions to prove his point. But Professor Kreiner’s new paper uses the
same groups of questions as Pisa and comes up with very similar results
to his initial analysis.
“He is sceptical about the whole concept of Pisa. “It is meaningless
to try to compare reading in Chinese with reading in Danish,” he said.
“Dr Morrison said that the Rasch model made the “impossible” claim of
being able to measure ability independently of the questions that
students answer. “I am certain this (problem) cannot be answered,” he
told TES.”
To read Dr. Kreiner’s studies, google his name.
1 comment:
Again we see how flawed assessment can be as well as how it can be manipulated by both the administering agent as well as the agency paying the bill. Unfortnuately, the general public doesn't have much of an understanding (and perhaps interest) beyond the headlines which these assessments and their supporters trumpet. Very few have the statistical understanding to recognize how these data and construded formulas can be misleading and manipulated to paint whatever picture a group wishes in order to maintain their desired position, perspective or power.
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