The PARCC and Les Perelman’s BABEL machine.


Les Perelman.

-This is an excerpt from The Washington Post’s Valerie Strauss column featuring a post by Leonie Haimson. Les Perelman is an old high school pal, retired director of the multi-discipline writing  program at MIT and an expert on computer scoring. Read the entire article here.

According to Les Perelman, retired director of a writing program at MIT and an expert on computer scoring, the PARCC/Pearson study is particularly suspect because its principal authors were the lead developers for the ETS and Pearson scoring programs. Perelman said: “It is a case of the foxes guarding the hen house. The people conducting the study have a powerful financial interest in showing that computers can grade papers.”

In addition, the Pearson study, based on the spring 2014 field tests, showed that the average scores received by either a machine or human scorer was “very low: below 1 for all of the grades except grade 11, where the mean was just above 1.”

Given the overwhelming low scores, the results of human and machine scoring would of course be closely correlated in any scenario.

Les Perelman concludes: “The study is so flawed, in the nature of the essays analyzed and, particularly, the narrow range of scores, that it cannot be used to support any conclusion that Automated Essay Scoring is as reliable as human graders. Given that almost all the scores were 0’s or 1’s, someone could obtain to close the same reliability simply by giving a 0 to the very short essays and flipping a coin for the rest. ”
As for the AIR study, it makes no particular claims as to the reliability of the computer scoring method, and omits the analysis necessary to assess this question.

As Perelman said: “Like previous studies, the report neglects to give the most crucial statistics: when there is a discrepancy between the machine and the human reader, when the essay is adjudicated, what percentage of instances is the machine right? What percentage of instances is the human right? What percentage of instances are both wrong? … If the human is correct, most of the time, the machine does not really increase accuracy as claimed.”

Moreover, the AIR executive summary admits that “optimal gaming strategies” raised the score of otherwise low-scoring responses a significant amount. The study then concludes because that one computer scoring program was not fooled by the most basic of gaming strategies, repeating parts of the essay over again, computers can be made immune from gaming. The Pearson study doesn’t mention gaming at all.

Indeed, research shows it is easy to game by writing nonsensical long essays with abstruse vocabulary. See for example, this gibberish-filled prose that received the highest score by the GRE computer scoring program. The essay was composed by the BABEL generator – an automatic writing machine that generates gobbled-gook, invented by Les Perelman and colleagues. [A complete pair of BABEL generated essays along with their top GRE scores from ETS’s e-rater scoring program is available here.]

In a Boston Globe opinion piece , Perelman describes how he tested another automated scoring system, IntelliMetric, that similarly was unable to distinguish coherent prose from nonsense, and awarded high scores to essays containing the following phrases:

“According to professor of theory of knowledge Leon Trotsky, privacy is the most fundamental report of humankind. Radiation on advocates to an orator transmits gamma rays of parsimony to implode.’’

Unable to analyze meaning, narrative, or argument, computer scoring instead relies on length, grammar, and arcane vocabulary to do assess prose. Perelman asked Pearson if he could test its computer scoring program, but was denied access. Perelman concluded:

If PARCC does not insist that Pearson allow researchers access to its robo-grader and release all raw numerical data on the scoring, then Massachusetts should withdraw from the consortium. No pharmaceutical company is allowed to conduct medical tests in secret or deny legitimate investigators access. The FDA and independent investigators are always involved. Indeed, even toasters have more oversight than high stakes educational tests.

A paper dated March 2013 from the Educational Testing Service (one of the SBAC sub-contractors) concluded:

Current automated essay-scoring systems cannot directly assess some of the more cognitively demanding aspects of writing proficiency, such as audience awareness, argumentation, critical thinking, and creativity…A related weakness of automated scoring is that these systems could potentially be manipulated by test takers seeking an unfair advantage. Examinees may, for example, use complicated words, use formulaic but logically incoherent language, or artificially increase the length of the essay to try and improve their scores.

The inability of machine scoring to distinguish between nonsense and coherence may lead to a debasement of instruction, with teachers and test prep companies engaged in training students on how to game the system by writing verbose and pretentious prose that will receive high scores from the machines. In sum, machine scoring will encourage students to become poor writers and communicators.

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