There are tests that have right answers, which are returned with a number on top in a red circle, and there are tests with open-ended questions, which provide insight into the test taker's mind.

The Rorschach test, a series of 10 inkblot plates created by the Swiss psychiatrist Hermann Rorschach for his book “;Psychodiagnostik,”; published in 1921, is clearly in the second category.

Yet in the last few months, the online encyclopedia Wikipedia has been engulfed in a furious debate involving psychologists who are angry that the 10 original Rorschach plates are reproduced online, along with common responses for each. For them, the Wikipedia page is the equivalent of posting an answer sheet to next year's SAT.

They are pitted against the overwhelming majority of Wikipedia's users, who share the site's “;free culture”; ethos, which opposes the suppression of information that it is legal to publish. (Because the Rorschach plates were created nearly 90 years ago, they have lost their copyright protection in the United States.)

“;The only winners seem to be those for whom this issue has become personal, and who see this as a game in which victory means having their way,”; one Wikipedia poster named Faustian wrote on Monday, adding, “;Just don't pretend you are doing anything other than harming scientific research.”;

What had been a simmering dispute over the reproduction of a single plate reached new heights in June when James Heilman, an emergency-room doctor from Moose Jaw, Saskatchewan, posted images of all 10 plates to the bottom of the article about the test, along with what research has found to be the most popular responses for each.

“;I just wanted to raise the bar — whether one should keep a single image on Wikipedia seemed absurd to me, so I put all 10 up,”; Heilman said in an interview. “;The debate has exploded from there.”;

Psychologists have registered with Wikipedia to argue that the site is jeopardizing one of the oldest continuously used psychological assessment tests.

“;The more test materials are promulgated widely, the more possibility there is to game it,”; said Bruce L. Smith, a psychologist and president of the International Society of the Rorschach and Projective Methods, who has posted under the user name SPAdoc.

He quickly added that he did not mean that a coached subject could fool the person giving the test into making the wrong diagnosis, but rather “;render the results meaningless.”;

To psychologists, to render the Rorschach test meaningless would be a painful development because there has been so much research conducted — tens of thousands of papers, by Smith's estimate — to try to link a patient's responses to certain psychological conditions. Yes, new inkblots could be used, these advocates concede, but those blots would not have had the research — “;the normative data,”; in the language of researchers — that allows the answers to be put into a larger context.

And, more fundamentally, the psychologists object whenever diagnostic tools fall into the hands of amateurs who have not been trained to administer them.

“;Our ethics code that governs the behavior of psychologists talks about maintaining test security,”; Steve J. Breckler, the executive director for science at the American Psychological Association, said in an interview. “;We wouldn't be in favor of putting the plates out where anyone can get hold of them.”;

Alvin G. Burstein, a professor emeritus of psychology at the University of Tennessee, Knoxville, wrote in an e-mail message that his preference was to have the images removed but that he did not think they would harm the psychological process.

“;The process of making sense of one's experience,”; he wrote, “;is gratifying. To take Rorschach's test is to make sense of ambiguity in the context of someone who is interested in how you do that.”;

Trudi Finger, a spokeswoman for Hogrefe & Huber Publishing, the German company that bought an early publisher of Hermann Rorschach's book, said in an e-mail message last week: “;We are assessing legal steps against Wikimedia,”; referring to the foundation that runs the Wikipedia sites.

“;It is therefore unbelievably reckless and even cynical of Wikipedia,”; she said, “;to on one hand point out the concerns and dangers voiced by recognized scientists and important professional associations and on the other hand — in the same article — publish the test material along with supposedly 'expected responses.' “;

Mike Godwin, the general counsel at Wikimedia, hardly sounded concerned, saying he “;had to laugh a bit”; at the legal and ethical arguments made in the statement from Hogrefe.

Hogrefe licenses a number of companies in the United States to sell the plates along with interpretative material. One such distributor, Western Psychological Services, sells the plates themselves for $110 and a larger kit for $185. Heilman, the man who originally posted the material, compared removing the plates to the Chinese government's attempt to control information about the Tiananmen massacre. That is, it is mainly a dispute about the control of knowledge, he said.

“;Restricting information for theoretical concerns is not what we are here to do,”; Heilman said, adding that he was not impressed by the predictions of harm from those who sought to keep the Rorschach plates secret. “;Show me the evidence,”; he said. “;I don't care what a group of experts says.”;

To illustrate his point, Heilman offered the Snellen eye chart, which begins with a big letter E and is readily available on the Wikipedia site, as a counterargument.

“;If someone had previous knowledge of the eye chart,”; he said, “;you can go to the car people, and you could recount the chart from memory. You could get into an accident. Should we take it down from Wikipedia?”;

And, Heilman confessed, “;My dad fooled the doctor that way.”;