Here's my testimony. It will probably be marked "not helpful" by people who are determined not to like JSL 1. However, I did want to share this discovery with people who are truly looking to learn. My accelerated Japanese class used this book. I dropped the class after a month, overwhelmed from learning the spoken and written languages concurrently. For some reason I kept the book, and it sat in my collection. I then picked up "The Structure of the Japanese Language" by Susumu Kuno and taught myself the kana using the Tuttle books. I was surprised to find that Kuno referenced Jorden's JSL! I had already paid for the JSL book so what was there to lose? There I went again, back into JSL.
Here is what I found after reading the introduction to JSL 1(very important to read the authors' introduction) and then applying the techniques.
Jorden approach works. She tells you what she's going to do, why she's going to do it and then proceeds to actually do it. That's why the inroduction to the book is important. How many of your teachers have ever explained why they do things a certain way and where it will lead? Her whole approach is centered on teaching Japanese in a way that would make sense to a native Japanese speaker. She uses terms like Nominals, Verbals and Adjectivals because conceptually, to a native Japanese speaker, the English concepts of Noun, Verb and Adjective DO NOT apply exactly. No where else had I seen this distinction explained. What's the point? Well, when you try and apply English grammar concepts wholesale to Japanese you are more likely to get it wrong. They are two distinct languages. Again and again, she makes the point of not getting trapped into "decoding" the language into English. "Decoding" the language is one thing. Knowing the language instinctively is completely different. Jorden gets you on the road to the latter.
She tells you why she uses a different romanization scheme. Why you ask? Well, the original schemes tried to map Japanese to English. Jorden's romanization tries to map English to Japanese. She factors in the phonetic profile of the Japanese language, how it actually sounds. Some students do not like the accent marks that are found throughout the book. However, you ABSOLUTELY need to know where the accents fall in a word or phrase, otherwise YOU ARE NOT SPEAKING JAPANESE. Japanese, like other East Asian languages, is a tonal language. If you mess up the accents, at best you will confuse your audience, at worst deeply offend them. Isn't it great that someone took the time to write the accents out? It's up to you to learn them. Also, once you've learned them, you've learned them!!!
There is no kana/kanzi in the book itself. That is not a big deal. I taught myself the kana using the Tuttle books. The kanzi will take separate dedicated study no matter what. Do you really want to learn the spoken language and a pictogram/ideograph based writing system simutaneously? Learning kanzi will actually slow you down because at the stage, you are still trying to learn to listen and speak, the HARDER skills. There are plenty of books and online resources for practicing kana/kanzi. Why not master one set of skills, the harder skills, and then move on to the relatively easier skills, reading and writing? Say you learn the kana/kanzi without first mastering the spoken language and someone asks you to read aloud. You will have no concept of what the language sounds like. Also, compare the number of opportunities you have to speak Japanese and the number of opportunities you have to read and write it. Which skills should get the most focus? Here's another analogy. There are a lot of musicians who can play music on sight but can not sing the notes without the help of an instrument. Learning how the music sounds before you ever touch an instrument is the hardest skill, but the most valuable in the long run. Learning the instrument itself is comparatively easier. In this case, you want to have the sound authentically in your head before you use your instrument, your voice.
The vocabulary is relatively limited. Again that is not a big deal. You can buy a Japanese-English dictonary and fix that problem easily. Jorden makes the point that learning new vocabulary only makes sense if that vocabulary is constantly enforced. Otherwise, YOU WILL FORGET IT. Again, why make your learning complicated? Learn what's in the book and you will get constant reinforcement in the tapes(a must have!!!!)
Also, don't be distracted or discouraged by the lack of pictures, etc, about Japanese life and culture. There are plenty of resources on the web that can remedy that. You probably want a book that will help educate you. There are already plenty of books that will entertain you with pretty pictures and such. However, does that honestly help you to hold a conversation? Lastly, while the conversation may be dated, again, that's not a big deal. How many native English speakers honestly have trouble understanding English movies and books from the 40s-60s? I would prefer to sound dated then wrong. People may respect the former but will ridicule the latter. What you should focus on is learning the harder skills first, Speaking and Listening and then move on to Reading and Writing. Jorden clearly announced her intentions by calling this: Japanese THE SPOKEN LANGUAGE.
A few final notes:
1. You absolutely, positively need the audio tapes(containing Core Conversations and Drills) for this series. The video tape is only useful for the Core Conversations so you can see the vocabulary used in text. The video tape of the Drills is a nice to have but isn't really worth the price because the audio tapes cover the same material.
2. Jorden makes the point that if you master the first chapter, you've built up all the skills to master the remaining chapters. Isn't that reassuring?
3. The books is actually 371 pages long.
4. Listen to some of the webcasts/broadcasts of Japanese from NHK and listen to how often you can pick out the vocabulary in JSL. I was suprised at how often they said "Soo desu nee/Soo desu ne", phrases which Jorden explained to death.
5. The JSL series represents a core. If you do not know this core, can you say you know Japanese?