The epistemology of document examination
The debate over the authenticity of the Killian memos has been very disappointing.
A lot of bloggers have been crowing about their ability to create documents similar to the Killian memos in Word. As Brian Weatherson notes, they are fallaciously affirming the consequent. Of course word processors can imitate typewritten documents. That's what they were designed to do! This is especially true if you already know what the Killian memos look like and set about duplicating them. The question is whether there is anything about the documents that's rare or impossible in typed documents but ubiquitous in word processed documents. So far, I haven't seen any evidence of that. The discredited typography allegations were intended to show that the documents couldn't have been produced by a typewriter. If the critics had found traits of the memos that would have been unlikely or impossible from a a typewriter but nearly universal from a word processor, that would have suggested that a word processor was responsible. In fact, without the typography claims, all the critics are doing with their homemade Word demos is pointing out that a similar but not identical document can be produced in Word. So far, no one has been able to produce a document in Word that is truly identical at the level that would convince a questioned document examiner. All that has been shown so far is that Word can do many of the same things as typewriters.
Matt Yglesias agrees that the right wing blogosphere has been peddling some specious arguments which unaccountably convinced real journalists to investigate further. Matt thinks that the latest Washington Post story comes closer to debunking the memos.
I disagree. Notice how this bullshit comes in waves? First typography. Then sourcing. Now military jargon. Just as the typography allegations get refuted, people start harping on the fact that the memos came from private files. Now we're on to the "doesn't match military jargon" narrative. Luckily for the right wing few of us are in a position to evaluate the jargon of the TANG in the 1970s. (Though arguably almost any sentient being is better position to know how people talked in the TANG in the 1970s than W.) Independent experts on the TANG are fewer still. Most people in a position to know are either gruntled or disgruntled TANG members. If the memos are real, the implication is that the Guard was disgracefully if not criminally corrupt. Though hardly conclusive, we should keep this fact in mind when weighing the WaPo's claims to have cross checked the Killian memos with documents recently released by the Guard itself. If the Guard released these records after the appearance of the Killian memos became public knowledge, we have to wonder whether they released a random, representative sample of the documents available.
Unaccountably, the supposedly compelling Washington Post article leads with the weakest point of their story, namely, that handwriting expert Marcel Matley can't vouch for the authenticity of the documents. As Matley explains, CBS asked to him to examine documents that were many photocopies removed from the originals. Therefore, he was only able to authenticate Killian's signatures, not the memos themselves. The Post article disingenuously ignores the fact Matley was only one of three forensic document examiners who vetted the memos on behalf of CBS. CBS hasn't released the names of the other two examiners or explicitly relayed their conclusions.
Matley didn't say that would have been impossible for anyone to authenticate documents like these. He just said that it was beyond his expertise to do so. We don't know where the expertise of the other two examiners lies or how strongly they endorsed the memos. Handwriting and typography are two sub-specialties within questioned document examination. No doubt, there are also people who specialize in projecting what original documents would have looked like based on assumptions about photocopying technology. Still others focus on historical, semantic, and stylistic details. We shouldn't necessarily assume that any one expert ought to be in a position to conclusively authenticate a document, even if that document is authentic.
What nobody really makes clear is the overall logic of questioned document examination. Generally speaking, documents are authenticated by comparing them to known examples of their type. Killian's signatures were authenticated by comparing them to known samples of Killian's handwriting. Matley was able to say that they matched the prototypes enough and in the right ways. He was also able to affirm that they didn't match each other or the prototype too much--it would have been a dead giveaway to have multiple identical tokens of the same signature type. Part of the expertise of a questioned document examiner lies in knowing what tends to vary and what tends to stay the same.
A questioned document examiner may also able to recognize characteristic ways in which evidence degrades. The Washington Post uncritically repeats the proportional font canard. In fact, the documents have been copied so many times that the type looks kerned because of cumulative distortions.
The Post story also cites Adobe type experts who claim that the width of the Killian font is closer to modern word processor editions of the same font than to what an IBM typewriter would have produced. The Post doesn't explain whether the type experts are also qualified to factor in the distortion induced by photocopying. One presumes not.
The Post also claims that there are stylistic and content inconsistencies in the memos. These questions can only be answered by comparison to known examples of the relevant sort. The TANG released some documents from the era, but the Post doesn't elaborate on what kind of documents they were or who wrote them. The Post story also claims that the memos are inconsistent with the historical record. For example, one of the people mentioned by Killian had already quit the Guard by the time the memo alleges that he was pressuring Killian. The memos also mention an address for W. that wasn't accurate at the time the memos were allegedly written. These are the sort of thing that, if substantiated, would raise doubts about the authenticity of the memos. At this point we can't assume that they accurate, given the sad history of factual allegations in this case (e.g., "There was no such thing as Times New Roman in 1972.") On the other hand, it's quite possible that a former TANG leader was pressuring Killian and that the Guard was still sending mail to Bush's parents' address. If I had a nickel for every institution that still sends mail to my old addresses, I'd be able to buy a PR firm and my own staff of experts.
A questioned document examiner should also be able to pronounce on the expected variability in a particular type of sample. For example, signatures always vary slightly on each instance. Some people have more consistent signatures than others. In order to differentiate between incriminating inconsistencies and natural variability it is important to compare documents within the relevant class. The mere fact that Killian's memos differ from some norms for Guard documents doesn't necessarily mean that the memos are forged. If someone compared my fridge-door shopping list with a written invitation in my best handwriting, they would observe all kinds of inconsistencies between the two. The disputed memos are Killian's "notes to self"--it would be interesting to compare the Bush memos to known informal memos by Killian.
Authentication is not some magic epistemological seal of approval. It's a judgment based on a accumulated balance of probabilities. Sometimes an expert has to conclude that the evidence is ambiguous. This appears to have been the case with Matley. He concluded that it was impossible to tell whether these were real memos with Killian's signature or faked memos with genuine signatures tacked on. If the physical evidence is ambiguous, it becomes necessary to turn to other sources. If the questioned document examiners were able to affirm that the documents could be real, the evidential burden shifts to the reporters. They must ask questions about the quality of the source, the plausibility of the provenance, the consistency of the content with our other well-founded beliefs about Bush's record, and so on.
Some commentators have complained that it's implausible that the memos came from Killian's private files. Mark Kleiman argues that the CBS story was "at best weakly sourced." We know that the CBS story was anonymously sourced. It may also have been weakly sourced, but we can't know unless CBS reveals its sources. CBS's reticence is an epistemological obstacle. How can we decide how good their evidence is if they won't share it with us? On the other hand, CBS and 60 Minutes are generally reliable sources. I have more confidence in their journalistic competence and integrity than I do in the ravings of the right-wing blogosphere, or the verdicts of self-styled outside experts assembled to pronounce authoritatively on the basis of evidence too flimsy to allow the CBS expert to positively identify the memos. The outside experts are even worse off than the inside experts because they relied on .pdfs of photocopies which introduced even more degradation and distortion.
Whether the "private document" story is plausible depends on details we don't know. Our view on the matter should depend on who allegedly produced these documents and what access they would have had to Killian. If I claimed that I had private documents from the secret files of Bush's former squadron commander, I'd be mocked. But that's because there's no plausible reason to think that I'd have access to that kind of information. However, if CBS knows that documents came from a former Killian employee or a close friend his, it would be more plausible that s/he might have acquired these private documents.
Addendum: Thanks to SoCal Justice for this link to an ABC story: allegedly, CBS's two other document examiners are claiming that they didn't vouch for the memos either. One claims that she sent an email to CBS urging them not to go ahead with the story because she had doubts about the memos' authenticity. I'd like to see that email. I'd have to question the integrity of the CBS team behind the story if I had evidence that she and her colleague explicitly told CBS that the documents were fake or even that they weren't credible enough to base a story on.
I do have to wonder why these experts didn't come forward earlier, though. It's one thing to say that you had doubts all along, it's another to prove it, and to prove that you expressed them forcefully when it counted. Remember how Hodges changed his story?