A few things....
1. You're teaching at a community college, right?
In public schools K-12, most students are given free use of a textbook which they return at the end of the year; so, there's no excuse for not having a textbook at the K-12 level. You and your students are in a different situation.
Does your department/college mandate or require that students buy the textbook, workbook, etc.? That's a big difference between K-12 and post-secondary institutions. In that situation, I think I would stress the importance of having access to a textbook as soon as possible. It seems obvious to me, but -having taught part time at a community college myself- you have to be very concrete with some students at the 101 level, especially the younger ones right out of high school or with the students who weren't stellar students in their earlier years and need more direction regarding post-secondary expectations.
Are the DVDs part of the textbook package that the students buys, or are they available in a lab, "Blackboard", or online at your or the department's website?
2. Regarding grouping. I would not use groups of three. The students in a group of three are not as engaged as they are in a group of two. The only time I use a group of three is if I have an "extra" student left over, and that student needs to be put into a group of three only as a last resort. Also, don't sit down and be that extra student's partner as you need to be floating around the room checking on student progress and reinforcing student accountability. This gives you feedback as the instructor regarding your pacing of instruction and how you need to adjust your teaching.
3. I know most college professors do NOT do this, BUT.... do a monthly seating chart for your ASL classes. Group them in pairs with a high and a low proficiency student in each pair. It doesn't have to be monthly... it can be every 3 or 4 weeks. Watch their various levels of proficiency. I've been a volunteer sign language interpreter using PSE (Pidgin Sign Language) in the past. My expressive skills are quite good with PSE, but my receptive skills are rather lousy. I can communicate well with a Deaf person who signs and voices a little and who knows how to communicate with a hearing person like me who uses PSE. SO.... As you are floating around the room, watch for expressive and receptive proficiency. That will help you with your "monthly" heterogeneous seating chart.
4. Are you giving some sort of classroom Class Participation & Home Work grade in your syllabus? Let me see if I can attach the forms that I have used in ESL and Latin classes. Please edit them to fit your needs and your students' needs for the ASL classroom. (I also have them in Spanish, French, German and Chinese. If you want to see any of those, let me know and I'll send them to you.) Have your students fill out these forms weekly. Make yourself several copies of your monthly seating chart for recording your observations week by week. Again, edit/revise my documents to fit your and the students' needs.
5. In an earlier posting, I mentioned having a set of 3x5 index cards, each card having a student's name on it. During the class period, after the students have done some partner work with their high/low partner, use your index cards to "deal out" different partners. That is.... the students will get up and move to work with a different partner. It is here that you can mix and match higher achieving students together. Or just follow the luck of the draw of the cards. Also, on these cards, you can make some notes about expressive and receptive proficiency using some sort of code. That will help you in grouping the students for these impromptu pairings. Or.... After the students enter class, sit down, and the tardy bell rings..... you could do some high/high and low/low pairing....then have them return to their seats and work with a high/low partner. It's your call as the teacher.
6. If you don't mind, go back and read my earlier posting about grouping, using index cards.....etc. Also, see if you can find "rich" visuals or line drawings of the Deaf interacting in real world situations with both the Deaf/HI and "hearing" people. Put a visual up on the screen.... Ask for "signs." Students will raise their hands and give you signs. You repeat their sign back to them...correct any miss-signing and give them a quick "great" or "good." Collect signs from several in the class. Get the pairs to practice the signs for 30 seconds or a minute. Then ask for a complete signed sentence about the visual. Of course the signers must get up and sign to the room using proper Deaf etiquette for doing so. After a few volunteers... and your "dignifying" their signed sentences by signing back to them.... Get them to practice in pairs. Then ask for question signs... Then have them get in pairs taking turns signing questions and answers to each other.
7. After they've worked with all of this vocabulary-expressively and receptively-bring out the DVDs.
8. Of course, you will want to float around during all of this noting what needs to be discussed, added, corrected....etc....
9. You will want to do some "checks for understanding," too. When it comes to practicing dialogs, use your deck of cards and have them practice with different partners in the room. They will improve practicing with each other and rehearsing with different people as well as signing with different people and "reading signs" off of different people.
10. When it's time to assess the dialogs [In your post you wrote going from individual to individual.... Or having two proficient students perform before you.] use your cards again. Put the entire class into a large circle. Then pull two cards from your deck and let those two start an improvised dialog based around the theme that your unit is stressing. You will have given them a rubric beforehand....regarding length of dialog, certain structures, a problem to solve together.... and if each individual has to do a "monologue" inside of the dialog. [A monolog being 4-6 sentences of extended discourse.] After they finish and you record a presentation grade for them, have the members of the class [the audience] sign a comment about what they just watched the "presenters" sign about. Keep a record of this as participation. And/or have the "audience" ask the presenters further questions about their dialogs, etc....
11. I remember my sign language classes. The teacher would sign. We would "repeat" or "copy." We as students never interacted with each other expressing our own thoughts within the confines of the vocab signs being learned. Sometimes we rehearsed "canned," memorized dialogs. Or we would get up and "make a presentation." It was always teacher/student. Not much student/student with teacher coaching.
12. BTW, when teaching Spanish, French, Latin, ESL.... I had my students learn those foreign alphabets along with finger spelling in ASL.... Also taught them the ASL numbers with the Spanish, French, Latin and ESL pronunciations. They learned how to finger spell their "foreign language" names with voice and finger spelling. In my travels, I have met a -very much in love- young German Deaf couple in Berlin, and we "chatted." In Buenos Aires I met a Deaf man at a restaurant and we "chatted." He told me about his School for the Deaf and which streets to avoid in Buenos Aires. A previous Miss Deaf Virginia was a Spanish major at Gallaudet... and we signed en espanol. Sign is great, too, for communicating under water-or behind "sound proof" glass. J End of commercial.
13. Being a foreign language teacher, I've always wanted to teach a bit of sign-but I am not certified. At one of our "Super Saturday" programs for the gifted and talented, I got to teach some PSE (but also told them about ASL and SEE) for 4 Saturdays. [One doesn't have to be certified to do those sorts of enrichment classes.] Mindful of my learning experiences, I made sure that they practiced frequently in various pairs and in communicative situations. At the same time, elsewhere, I was teaching zero level/entry level ESL classes. I taught my sign language students the signs from the beginning chapters of the ESL (English as a 2nd Language) on greetings with some Deaf etiquette, clothing, colors, food..... so that they would have a communicative context within which to practice with different partners. [I myself had never learned to sign "nice to meet you," until I met "real" Deaf people... although I knew all those signs in isolation from my classes.]
14. I hope this will help you some. Keep up the good work. ASL is a precious treasure. In ASL are all the joys and sorrows, hopes and dreams of our Deaf community and of those who love and befriend them. You are unlocking the door to that wonderful world for your "hearing" students. Once you step through that portal, your life and experiences are that much richer. J
Robert L. "Bobby" Oliver