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Dr. Bill's "Caterpillar Model" of ASL Curriculum Development

Some curriculum developers believe in a prescriptive approach (telling you what "should" be done), I believe in a descriptive approach (telling you what "is" being done). 

American Sign Language is constantly changing, developing, and growing to fill the needs of the Deaf Community.


The Deaf Community as a whole decides over time whether to accept or reject any particular sign or usage of a sign.


American Sign Language is a lot like a caterpillar.  As a caterpillar moves forward quite often it gets bunched up in the middle.

OLD SIGNS...Caterpillar Model of ASL Instruction (Dr. Bill)...NEW SIGNS...


It would be silly to say that the head or the tail isn't "part of" the caterpillar.  Obviously they are both very much indeed part of the body of the caterpillar. 


The reason caterpillars move like this is because they have a LOT of segments and not all segments are ready to move forward at the same time.


This is the same as the Deaf Community.  Our community has many segments and not all segments are ready to move forward on adopting any particular sign at the same time.  Therefore you will get some people who adopt a sign early, a bunch in the middle, and some who are slow to catch up.

As instructors and curriculum designers our job is to keep an eye on the caterpillar and make informed choices regarding when to decide a sign is "popular enough" to teach to our students.  For example, when I saw that the sign for Obama ("O-flag" version) had become sufficiently widespread I went ahead and posted that version to my website and listed it as one of several variations of the sign.

In a meeting a while back, a colleague expressed that he felt the "O-flag" sign wasn't reflective of ASL "rules" (as codified by a popular author in a book about name signs) and that the "O-flag" sign seemed like it had been influenced too much by English.

I replied that as a lexicographer (dictionary maker) it isn't my goal to prescribe what signs "should be" it is my goal to describe what signs are actually being used in the Deaf community. He replied that as a teacher my job is to make sure the students know the "right way" to sign.

To which I agreed totally. To me the "right way" to sign is the way of signing that is being done by the majority of the native Deaf community.

I strive to show numerous variations on my website.  In the local (in-person) classroom it is my job to be aware of which signs are used locally by native Deaf adults. In the classroom I show students the sign that is generally used in our region and--when appropriate--I mention that they might see it done other ways and give examples.

It is important for ASL teachers to get "out there" in the community and see what is being signed and be aware of the evolution of signs.  For example, the "OBAMA" sign continued to undergo change--becoming more "ASL-like" with only two movements (instead of three) and using a simple O-B handshape transition. It is common to see the president's name spelled out or done with a single movement that snaps from an "O" to a sideways, palm-back "B" -- sort of representing a "flag."

As I go about the process of deciding which signs to post to the Lifeprint Online ASL Dictionary and the Lifeprint Lessons I have found that a systematic multi-step approach is the best way to go:

First I think about what sign I personally use. I am Deaf/hh and live in the Deaf world. So I consider where I learned any particular variation of a sign and why do I think it is valid.  Next I consider how my (Deaf) wife signs it. Next I compare numerous American Sign Language dictionaries and textbooks to see how the sign is demonstrated in the literature by other experts. Often the dictionaries conflict with each other but generally a dominant sign tends to emerge. After doing a thorough review of the literature it is time to interview a cross section of Deaf adults who have extensive experience signing.

For example, (as of this writing) I teach ASL at California State University, Sacramento where there are several (currently five) full-time PhD-level ASL instructors and about 10 part-time instructors (most of whom are native Deaf) with decades of ASL teaching experience. In addition to my coworkers, the majority of my friends are Deaf. My wife's first language was ASL (simultaneous bilingualism: Bilingual/bicultural Deaf program). I go to a Deaf church. Most of my close friends are Deaf (or Codas, or terps). On a frequent basis I interact with a cross section of Deaf adults. This is what is known as being immersed in the Deaf Community. I make it a goal to interview a minimum of 10 advanced Deaf signers as to how "they" do the sign that is being considered for posting to the Lifeprint dictionary. I also drive my interpreters nuts (or perhaps amuse or entertain them) with my frequent interruptions of their interpreting to ask them how they sign various signs. Freelance interpreters are particularly helpful in this regard because they see and interact with numerous Deaf individuals from a wide variety of signing backgrounds.

The next stage of investigating a sign is to consider how the sign is done in other locations and decide which version is more widely used. I've lived in California, Utah, Texas, Indiana, Oregon, Maryland, and Washington D.C. (at Gallaudet in Benson Hall). My friends and co-workers have lived all over the map.

Next I post the sign online to my website where it is exposed to the scrutiny of thousands of individuals -- some of whom feel compelled to email me for the express purpose of informing me that I'm "wrong" and that their version is better or "right."  Or they will see me in person at a meeting and come up to me and tell me the sign I've got posted is "wrong." (Note the quote marks I have placed around "right" and "wrong.")

Two recent examples:

The sign for "party."
On my website I indicated that one of the variations of the sign "PARTY" was the same as the sign for "PLAY." An ASL instructor emailed me to say that "PARTY" and "PLAY" are distinguished by differences in the movement of the signs. He indicated that the right way to sign PLAY is that the arms stay stationary and the wrists twist. He stated that for the sign PARTY the wrists stay straight and the arms swing back and forth.

Of course I switched into lexicographer mode and immediately started surveying a large number of skilled local signers as to how they did the sign PARTY.

After quite a bit of additional research I remained convinced that both the "swinging" version and the "twisting" version are in widespread use.  It is was also apparent at that time the version of "PARTY" that used a twisting movement was becoming increasingly popular.

So which way is the "right way?" I believe it is safe to say several versions of PARTY are right (used by adult native Deaf people), but an interesting note told to me by one of my interviewees, Erika Geiger (d/Deaf), was that while she was a student at CSD (California School for the Deaf, Fremont) her class was planning an event. During a planning meeting the students began discussing having a party as part of the event. Erika did the sign "PARTY" using "P" hands and a twisting movement. Her teacher replied that "ahem" it was going to be a "party" not a "partay!" (Spelling intentional.) Erika explained to me how the teacher deliberately inflected an "old stuffy" sign for PARTY (a controlled, somewhat slower, larger, side to side swinging movement using "P" hands) to emphasize that this would be a classy "party" and not a rowdy party. (Interesting: Deaf School, Deaf student, Deaf teacher, classroom full of Deaf students, and both examples of the PARTY sign were 'initialized" with and English letter. In consideration of the example above, ask yourself: Should an ASL dictionary include initialized version examples that are in widespread and long-term use among Deaf people? (For me the answer is certainly "yes.")  To be clear though I certainly do feel that the non-initialized swaying-Y-hands version of PARTY should be the main entry for that term in an ASL Dictionary.  However that doesn't mean we should delete all other entries.

Another example: The "Hanukkah" entry.
I posted a sign for Hanukkah at Lifeprint.  I had spelled it "Hanukah." Soon after I got an email from someone regarding my spelling:

"Ecdrury" writes:
<<I let you know your lesson is H and Hanukah is wrong spells and Its actual is meaning: Hanukkah

To which I replied,
<<Dear Ecdrury,
According to there are three accepted spellings:
"Hanukkah or Hanukah also Chanukah."
But now I have a vote from you for the longer spelling.
Thanks for sharing your comment.
Dr. Bill>>

He was very polite in his reply -- which I appreciated.  I decided I had better keep an eye on that spelling issue.

Sure enough, a few years later I checked the site again.  Guess what?!  The shorter spelling had been deleted!   So I went back to and updated the entry to be "Hanukkah" and changed the name of the page to what seems to be the most popular spelling. Language evolves.

Then one year in December I signed "Happy Hanukkah" to an individual who promptly told me that my palm orientation was "wrong."  I thanked the person for the correction and went about having a merry Christmas.

Of course I grabbed my lexicographer's hat and started digging around -- uncovering the following versions of HANUKKAH (or Chanukah) at the time:

* Palms forward version: Michigan ASL Browser, The ASL Handshape Dictionary (book), and "Learning ASL" (book).

* Palms backward version: Lou Fant's "ASL Phrase Book", Elaine Costello's "Religious Signing" (book), and  (Source:

* Unusual version: - at the time of this research they were using a very stylized movement that ended up "palms back."

4: * Both palm back and palm forward versions: Random House ASL Dictionary (two different entries).

So you can see why it is important for ASL teachers (and/or other language "professionals") to be very careful about claiming to be "right" and telling others they are "wrong."

This near constant process of refinement via critique and research helps me become quite comfortable listing the variations that I do at because I can verify them from my interviewee pool, as well as in the literature and online. The research also gives me a feeling for which signs are gaining prominence and which ones are fading away. For another example of this process see: MEXICO ( and scroll down to the notes/discussion area.

I'm fortunate to have a lot of input from teachers and curriculum developers who teach using Lifeprint (LP) as their "text" and frequently submit ideas for improvements.

What is really neat about LP is that it is so easy to make improvements. It is rare that a day goes by without something being added, scrapped, fixed, or revised. The LP that exists today will not be the same that exists tomorrow.

Indeed, I welcome all questions, comments or suggestions regarding Lifeprint (LP). Knowing what people think allows me to keep making this a better resource.

Thank you for your interest.
Take care.

Dr. Bill
William G. Vicars, Ed.D.

Also see: Dr. Bill's "RPM Teaching Method"