VALUTAZIONE nei COLLEGE USA: Crisi nazionale
Valen E. Johnson, professore alla Duke
University di “Statistics and Decision Sciences”, ha condotto, per conto del Los
Alamos National Laboratory, un’analisi statistica sul sistema di valutazione
nelle Università statunitensi. Il titolo del libro, di prossima pubblicazione,
è: “College Grading: A National Crisis in Undergraduate Education”.
In sintesi, Johnson documenta come la valutazione assegnata dai docenti agli
studenti universitari sia poco oggettiva. E che la valutazione “A” assegnata da
un docente che dà solo “A”, conta meno di una valutazione “A” assegnata da
docenti che valutano anche con “B e C”.
Oltre 5 anni fa, alla Duke University più del 45% degli studenti era valutato
con “A”, mentre meno del 15% riceveva “C”. E quasi tutte le Università seguivano
questo trend. Quest’anno accademico gli Usa hanno subito uno shock dal risultato
delle votazioni universitarie: metà degli studenti sono stati valutati con A (o
A meno), mentre al 91% dei laureati è stata assegnata la lode. “Un collasso
nella valutazione critica fra le facoltà umanistiche” è il commento del Rettore
dell’Università di Harvard, Harry R. Lewis, come riportato sul giornale Boston
Globe.
La ricerca di Johnson mostra anche come le valutazioni assegnate da docenti
delle facoltà umanistiche siano significativamente più elevate di quelle
assegnate dai loro colleghi di facoltà scientifiche, in particolare scienze e
matematica. Ciò comporta uno spostamento delle scelte degli studenti verso
quelle materie e quegli insegnanti che assicurano loro una più alta valutazione,
indipendentemente da quanto bravi siano gli insegnanti e da ciò che da loro
possano apprendere. E’ quindi inevitabile un impoverimento della cultura
scientifica della nazione.
Se si tiene conto che negli Usa i corsi più finanziati, generalmente, sono
quelli più seguiti dagli studenti, si può comprendere come le scelte dei corsi
facoltativi, attivati per scienze e matematica, siano ridotte anche del 50%
rispetto ai corsi di materie umanistiche. E ciò crea un enorme squilibrio fra le
risorse assegnate ai dipartimenti di materie scientifiche e umanistiche.
Come rimediare? L’articolo di Johnson, riportato dal New York Times, non lo
rivela. Aspettiamo perciò di leggere gli altri capitoli del libro, non appena
uscirà. Nel frattempo, ci piacerebbe che il nostro Ministro Moratti, leggendo
queste analisi, realizzate non già da detrattori del sistema d’istruzione
statunitense, ma da esperti “interni”che, con lucidità, ne diagnosticano i punti
deboli, riducesse i Suoi entusiasmi verso l’americanizzazione del nostro sistema
d’istruzione.
Come da Sua dichiarazione, riportata su Repubblica del 26 agosto 2001, tra il
sistema universitario italiano e quello statunitense, il confronto non regge: ”
C’è da mettersi le mani nei capelli ” affermava la Moratti. (Anche per la
percentuale USA dei laureati con lode ( 91%), che ricorda molto la percentuale
degli studenti promossi dalle nostre commissioni (esterne) agli esami di Stato.
A proposito, avrà ascoltato il Ministro l'intervento del senatore Asciutti,
presidente della Commissione Cultura del Senato, nell'ambito del Meeting
internazionale a Milano "L'educazione e l'istruzione nel XXI secolo?
Dice Asciutti:" La nuova composizione delle commissioni degli esami di Stato va
rivista, perchè così com' è stata modificata dalla legge finanziaria 2002, con
tutti i membri interni dei consigli di classe, non va. Si rischia di dare
segnali che vanno in controtendenza rispetto al progetto complessivo di riforma
voluto dal ministro Moratti".)
E poi, quanto cara è la frequenza alle Università Usa? Con l’equivalente del
costo di un loro anno accademico, in Italia ci si potrebbe abbondantemente
pagare l’intero corso di laurea. Il problema non è solo migliorare il sistema
d’istruzione italiano, ma migliorarlo a costi sostenibili per l’intera
collettività. (S.C.)
An A Is an A Is an A ... And That's the Poblem.
By VALEN E. JOHNSON
May 1997, the Arts and Sciences Council at Duke University
rejected a proposal to change how grade point averages were computed. The new
formula accounted for variations in the grading policies of different professors
and departments. For instance, A's awarded by professors who gave only A's would
count less than A's from professors who also handed out B's and C's. Not
surprisingly, the proposal, which was mine, proved to be quite controversial.
Easy graders objected to the implication that their A's were somehow less
valuable than the A's awarded by others. Of the 61 council members, 19 voted
against the proposal (except for one, they were all humanities professors),
while 14 voted in favor (all science and math). I suspect the idea would have
fared better if the N.C.A.A. basketball tournament had not started that
afternoon -- humanities professors are not into Duke basketball the way science
professors are. The proposal was the outcome of a committee convened by the
provost to discuss grade inflation. More than 45 percent of Duke undergraduate
grades at the time were A's of one flavor or another, and fewer than 15 percent
were C-plus or lower. Five years later, little has changed at Duke or elsewhere.
Nearly every university in the country has experienced a similar trend. In fact,
Duke is barely keeping pace with its peers. This academic year the country was
shocked -- shocked! -- over the revelation that half of all undergraduate grades
at Harvard are A or A-minus, and that 91 percent of last June's graduates walked
off with Latin honors. Some attribute the inflationary trend to a degradation of
academic standards -- ''a collapse in critical judgment'' among humanities
faculty, as Harry R. Lewis, the dean of Harvard College, told The Boston Globe.
Others invoke the more popular explanation that grade inflation is the byproduct
of rapidly improving student bodies and a heightened emphasis on undergraduate
teaching, and that higher grades have no effect on post-secondary education as a
whole. In a two-semester experiment in 1998-99, several colleagues from Duke's
Committee on Grades joined me in investigating these arguments, conducting an
online study with student course evaluations. Among other issues, we examined
the influence of grades on evaluations (or, as some assert, can students judge
teaching independently of how they do in a course?) and on which courses
students enroll in (or are they too high-minded to let a potentially low grade
affect their decision?). About 1,900 students participated, providing more than
11,500 complete responses to a 38-item evaluation of courses they were either
currently enrolled in or had taken the previous semester. Freshmen completed
evaluations for fall courses twice, before receiving a final grade and after,
allowing us to measure the effects their grades had on how they evaluated the
teacher. The results were startling. Freshmen expecting an A-minus were 20 to 30
percent more likely to provide a favorable review than those expecting a B, who
were 20 to 30 percent more likely than those expecting a C-plus, and so on.
After the course was over, students changed their assessments: on average, those
who did not get the grade they had anticipated lowered their evaluation, and
those with higher marks gave more favorable evaluations. Because the same
students were rating the same instructors, teaching could not account for the
change of heart. Something else was at play. Lenient graders tend to support one
theory for these findings: students with good teachers learn more, earn higher
grades and, appreciating a job well done, rate the course more highly. This is
good news for pedagogy, if true. But tough graders tend to side with two other
interpretations: in what has become known as the grade attribution theory,
students attribute success to themselves and failure to others, blaming the
instructor for low marks. In the so-called leniency theory, students simply
reward teachers who reward them (not because they're good teachers). In both
cases, students deliver less favorable evaluations to hard graders. Our
experiment, building on previous grading research, offered strong evidence
supporting the views held by the tough graders. The second goal of our study was
to examine the influence grading policies exert on the courses students decided
to take. As an incentive for participating, students were given the opportunity
to view summaries of the evaluations that were entered by other students, along
with mean grades of courses taught in the past (another aspect of the experiment
that didn't exactly endear us to Duke faculty). Over the course of the
experiment, students looked at more than 42,000 mean grades (about four times
the number of course evaluations that were inspected). Grading influence was
then statistically assessed by matching the mean grades the students examined to
the courses they subsequently took. The results are perhaps best illustrated
through this example: in choosing between two different instructors of the same
course -- one who grades at an A-minus average and another a B average --
students were twice as likely to select the A-minus instructor. Similar
conclusions applied when students chose among different courses. For instructors,
the implications could be significant. In addition to receiving fewer favorable
evaluations, a tough grader may also attract fewer students. Because most
departments are hesitant to devote resources to classes with low enrollments,
specialized courses in a tough-grading professor's area of interest may be
dropped. And, of course, to the extent that personnel decisions are based on an
institution's perception of teaching effectiveness, they may be less likely to
be rewarded with tenure, promotions or salary increases. For higher education in
general, the implications could be even more significant. Different grading
philosophies among disciplines can potentially create shifts in enrollments --
specifically, from natural sciences and mathematics to the humanities. The Duke
study confirmed the common belief that natural science and math classes are
graded the hardest and humanities the easiest. After all, an essay is far more
subjective to assess than multiple-choice answers, especially for the
postmodernist professor -- but low grades are also harder to justify to angry
students and parents. The difference between the most leniently graded
department in the study (music, with a mean grade of 3.69) and the most
stringently graded (math, with a mean of 2.91) was almost an entire letter grade.
Moreover, departments that graded easiest, including literature, Spanish and
cultural anthropology, tended to have the least able students as measured by SAT
scores and college and high school G.P.A. For elective courses, the mean grade
awarded in humanities was 3.54; in social sciences 3.40; and in natural sciences
and math 3.05. Coupled with the effects grades have on student course selections,
these differences portend a 50 percent reduction in the number of elective
courses taken in natural sciences and math. This figure is consistent with
studies conducted at Williams College in 1991 by Richard H. Sabot and John
Wakemann-Linn, who estimated the probabilities that students would take a second
course in a discipline based on their grade in the first. Among the potential
fallout is a disproportionate allocation of resources to humanities departments
at the expense of science departments. And students who might have chosen a math
or science course as an elective might turn elsewhere because of the specter of
earning a C, possibly diminishing science competence in the general population.
Opponents of change, often high-grading faculty, continue to argue that the
system isn't broken and doesn't need fixing. But grade inflation and, perhaps
more important, differences in grading philosophies, distort student and faculty
assessments. Students tend to select courses with teachers who grade leniently,
often learning less along the way. Uneven grading practices allow students to
manipulate their grade point averages and honors status by selecting certain
courses, and discourage them from taking courses that would benefit them. By
rewarding mediocrity, excellence is discouraged. Valen E. Johnson is conducting
statistical analysis for the Los Alamos National Laboratory while on leave from
Duke University, where he is a professor of statistics and decision sciences.
This essay is adapted from his forthcoming book, ''College Grading: A National
Crisis in Undergraduate Education.''