I’m not the only linguist in my family. My father has worked as a professional linguist his whole life… but with a slightly different definition of “linguist”. His job is to use his specialist knowledge of a language (specifically Mandarin Chinese, Mongolian or one of the handful of other languages he speaks relatively well) to solve a problem. And one problem that he’s worked on a lot is language learning.

There’s no doubt that knowing more than one language is very, very useful. It opens up job opportunities, makes it easier to travel and can even improve brain function. But unless you were lucky enough to be raised bilingual you’re going to have to do it the hard way. And, if you live in America, like I do, you’re not very likely to do that: Only about 26% of the American population speaks another language well enough to hold a basic converstaion in it, and only 9% are fluent in another language. Compare that to Europe, where around 50% of the population is bilingual.

I should mention that Dr. Pimsleur was an academic working in second language acquisition from an applied linguistics stand point. That is, his work (published mainly in the 1960’s)  tended to look at how older people learn a second language in an educational setting. I’m not saying this makes him unimpeachable–if a scientific argument can’t stand up to scrutiny it shouldn’t stand at all–but it does tend to lend a certain patina of credibility to his work. Is it justified? Let’s find out.

First things first: it is not possible to become fluent in a language in just ten days. There are lots of reasons why this is true. The most obvious is that being a fluent speaker is more than just knowing the grammar and vocabulary; you have to understand the cultural background of the language you’re studying. Even if your accent is flawless (unlikely, but I’ll deal with that later), if you unwittingly talk to your mother-in-law  and become a social pariah that’s just not going to do you much. Then there are just lots of little linguistic things that it’s so very easy to get wrong. Idioms, for example, particularly choosing which preposition to use. Do you get “in the bus” or “on the bus”? And then there’s even more subtle things like producing a list of adjectives in the right order. “Big red apple” sounds fine, but “red big apple”? Not so much. A fluent speaker knows all this, and it’s just too much information to acquire in ten days.

That said, if you were plopped down in a new country without any prior knowledge of the language, I’d bet within ten days you’d be carrying on at least basic conversations. And that’s pretty much what the Pimsleur method is promising. I’m not really concerend with whether it works or not… I’m more concerned with how it works (or doesn’t). There are four basic principals that the Pimsleur technique is based on.

1.  Anticipation. Basically, this boils down to posing questions that the learner is expected answer. These can be recall tasks, asking you to remember something you heard before, or tasks where the learner needs to extrapolate based on the knowledge they currently have of the language.
2. Graduated-interval recall. Instead of repeating a word or word list three or four time right after each other, they’re repeated at specific intervals. This is based on the phonological loop part of a model of working memory that was really popular when Pimsleur was doing his academic work.
3. Core Vocabulary. The learner is just exposed to basic vocabulary, so the total number of words learned is less. They’re chosen (as far as I can tell, it seems to vary based on method) based on frequency.
4. “Organic learning”. Basically, you learn by listening and there’s a paucity of reading and writing. (Sorry about that; paucity was my word of the day today 😛 ).

So let’s evaluate these claims.

1. Anticipation. So the main benefit of knowing that you’ll be tested on something is that you actually pay attention. In fact, if you ask someone to listen to pure tones, their brain consumes more oxygen (which you can tell because circulation to that area increases) if you tell them they’ll be tested.  Does this help with language learning? Well. Maybe. I don’t really have as much of a background in psycholinguistics, but I do know that language learning tends to entail the creation of new neural networks and connections, which requires oxygen. On the other hand, a classroom experience uses the same technique. Assessment: Reasonable, but occurs in pretty much every language-learning method. 
2. Graduated-interval recall: So this is based on the model I mentioned above. You’ve got short term and long term memory, and the Pimsleur technique is designed to pretty much seed your short term memory, then wait for a bit, then grab at the thing you heard and pull it to the forefront again, ideally transferring it to long-term memory. Which is peachy-keen… if the model’s right. And there’s been quite a bit of change and development in our understanding of how memory works since the 1970’s. Within linguistics, there’s been the rise of Exemplar Theory, which posits that it’s the number of times you hear things, and the similarity of the sound tokens, that make them easier to remember. (Kinda. It’s complicated.) So… it could be helpful, assuming the theory’s right. Assessment: Theoretical underpinnings outdated, but still potentially helpful. 
3. Core Vocabulary. So this one is pretty much just cheating. Yes, it’s true, you only need about 2000 words to get around most days, and, yes, those are probably the words you  should be learning first in a language course. But at some point, to achieve full fluency, you’ll have to learn more words, and that just takes time. Nothing you can do about it. Assesment:  Legitimate, but cheating. 
4. “Organic learning”: So this is in quotation marks mainly because it sounds like it’s opposed to “inorganic learning”, and no one learns language from  rocks. Basically, there are two claims here. One is the auditory learning is preferable, and the other is that it’s preferable because it’s how children learn. I have fundamental problems with claims that adults and children can learn using the same processes. That said, if your main goal is to learn how to speak and hear a given language, learning writing will absolutely slow you down. I can tell you from experience: once you learn the tones, speaking Mandarin is pretty straightforward. Writing Mandarin remains one of the most frustrating things I’ve ever attempted to do. Assessment: Reasonable, but claims that you can learn “like a baby” should be examined closely. 
5. Bonus: I do agree that using native speakers of the target language as models is preferable. They can make all the sounds correctly, something that even trained linguists can sometimes have problems with–and if you never hear the sounds produced correctly, you’ll never be able to produce them correctly.

So, it does look pretty legitimate. My biggest concern is actually not with the technique itself, but with the delivery method. Language is inherently about communicating, and speaking to yourself in isolation is a great way to get stuck with some very bad habits. Being able to interact with a native speaker, getting guidance and correction, is something that I’d feel very uncomfortable recommending you do without.