Often I hear of children "plateauing" in their home programs. While one can't just say that "a kid is bored" or "a team is boring" without knowing that child and the situation specifically, the things mentioned here are effective teaching practices that should always be in place.
First of all, effective use of reinforcement: It's easy to forget what reinforcement is -- it's not what YOU think should be reinforcing (even if it usually is, or was in the past) but what functions as a reinforcer for your child at any given moment. MO/EO, satiation, and all elements of reinforcement and motivation factor into each moment of teaching. Something that's usually not a strong reinforcer (water, for example) can become one if the situation is set up in a certain way (after feeding the child a lot of salty pretzels). Conversely, something that's usually a very strong reinforcer will lose its effectiveness once the child is satiated. Reinforcer effectiveness and preference need to be assessed constantly. That's one reason why I tell all my teams to probe every few trials with a mini-preference test. It's very easy. Hold up two reinforcers (A and B) and say, "What do you want?" or "Which one?" or some sort of choice antecedent. If the child chooses A, then offer a choice between A and C. If the child still chooses A, you know it's a strong reinforcer. This only takes a minute and it ensures that the child is always working for something s/he wants. Whatever form of reinforcer assessment you use, just make sure to note whether the item is truly functioning as a reinforcer. Is the behavior you're targeting increasing in occurrence as a result of the consequence you're delivering? If not, the item is not functioning as a reinforcer.
Schedule of reinforcement is another important issue. You can be assessing reinforcers constantly, have a buffet of preferred items, and still not be using the reinforcers effectively enough because the schedule is too thin, too thick, or static. Are you thickening the schedule of reinforcement for difficult tasks? Thinning it for easier tasks? Are you differentially reinforcing depending on the task? If the rate is good, are you reinforcing correctly? Shaping up responses through effective consequation of those responses? If the child is working really nicely, are you ultimately punishing that behavior by working him/her too long or too hard, since s/he's "on a roll"? Are you trying to make yourself more reinforcing, rather than giving up or getting frustrated, if the session isn't going well? Are you reinforcing collateral behaviors, such as attending, and "catching the child being good"? Are you yourself a reinforcer for the child? There's a lot more to reinforcement than meets the eye.
Another issue is rate of teaching. Are the teachers presenting material too quickly or too slowly? Are they familiar enough with the curriculum to be truly engaged in teaching or are they paying more attention to the STOs, or the data, or the materials, and not enough to your child? Are they running the programs correctly? Are they prompting enough? Too much? Are they attuned to the child such that their teaching behavior is shaped by the child's behavior? Finally, are the tasks appropriate? If the teaching is topnotch and the child is still not learning, then the task itself is probably the culprit.
There are so many variables in an ABA program to keep track of, but the teaching is probably the most important; only curriculum comes close, in my opinion. As I mentioned above, the behavior of effective teachers is constantly shaped by the child's behavior. Teaching is a collection of moment-to-moment reactions and decisions. Novice teachers are, by definition, not fluent teachers and, as such, they are more prone to making teaching errors, which need to be corrected and shaped through feedback. You need to teach your staff how to teach, which can also be accomplished using the principles of ABA. Shape their behavior. Reinforce them for effective and creative teaching. Correct teaching errors, but don't punish them. Catch them being good. To oversimplify, reinforce anything you want to see more of and correct any errors as they occur so they don't become learned.
Obviously, just as teaching with ABA should never be condescending to the child, it shouldn't be to the staff, either. I'm not saying to shove an M&M in the teacher's mouth and say, "Good teaching effectively!" Their training program needs to be individualized, just like the student's curriculum. And the same rules apply: When you reinforce the staff, make sure you're using something that functions as a reinforcer for them. Analyze the results of your feedback on their teaching and adjust your behavior accordingly. Staff that are effective want to come to work and to work harder, since their effectiveness results in more learning for the child and reinforcement from the family. Remember, the student is always right, and while your child is the staff's student, the staff are your students and your consultant's students. If they're not teaching effectively, that falls to the person who trained them, and so on. It all works out, though, because ultimately everything is Skinner's fault! ;) In all seriousness, though, this approach to training staff may sound like a lot, but it will give you a better staff, I guarantee you. Training effective teachers is probably the best thing you can do for your child.
Bottom line in all of this: When the child is not learning, the teaching is almost always responsible. Note that I said "the teaching," not the teacher. It's very hard sometimes for teachers, especially novice ones, not to take feedback personally. I think that's one reason why having data on teaching available to the team is a good idea. Data are objective. They also hold the teachers accountable for their behavior. This is true of both student and teacher data. If you decide to take data on your teaching, do so for all the elements of effective teaching. Have teachers graph their total trial presentation for the day (always within the same time period, to keep a consistent scale), as well as the total correct trials for the child (on the same graph). These two are linked because high rates of accurate teaching usually lead to increased learning for the child. The two should ascend together. Also, have them graph number of trials to criteria by calculating how many trials they present before the child meets a criterion. You can add in cumulative number of criteria, too, so that they can see how much learning is going on in another way. Then teach them how to use these data not for competition, but to improve their teaching. By analyzing each other's data, staff might see, for example, that one teacher is especially effective and they might then use her/his teaching as a model for their own. They should also be reinforced by the student's learning and by their own as demonstrated on the graphs. But be careful not to turn this into a competition or to show favoritism; if handled poorly, this sort of thing can turn ugly. Handled well, though, it can be a godsend to your team and, in turn, to your child.
A note on data: Data for data's sake are useless. Unless the data are guiding teaching, you might as well stop taking them. Again, novice teachers are usually not taught how to analyze and interpret data properly. When you train staff, explain WHY you take data, not just how. Explain that the data are all student-driven. They are the record of whether or not the child is learning. If you're not seeing ascending trends and criteria being met, something in the teaching needs to be changed. If the team can look at the data as their guide, rather than as a meaningless chore, they'll come to appreciate them more and to internalize their function. That way, even before they've graphed, they'll be thinking of the child's responses in a different way. If, mentally, they're envisioning a descending trend AS they're teaching, they can key into the notion of "Something in my teaching isn't effective; what do I need to be doing?" Then they can take a quick, in situ look at their teaching and adjust different elements. With fluent teachers, this all happens like breathing; it's reflexive and happens constantly and instantly. This is why ABA people are considered scientists of teaching.
I know, this is all well and good if you've got a team of teachers with grad level training in ABA, which is typically far from reality, but with a team of novices, it can't just be automatically expected. What I try to impart to staff when I train them is not to ape one particular person's teaching style, but to internalize the science as much as possible. I think teachers get into trouble when they think that a certain implementation IS the science of ABA. Blindly mimicking a person or an approach is harmful because then you get into the mode of topography over knowledge. Looking like you know what you're doing and actually knowing how to do it are two VERY different things. If you give your staff an understanding of the science, which doesn't have to be overly technical, just comprehensive and accurate, they'll be much better prepared to improve as teachers. Being rule-governed is good to a degree because the mechanics of ABA are important. But knowing the mechanics without understanding the science is like speaking a foreign language phonetically. Teachers can't be expected to adjust their teaching to the child's behavior if they don't know enough to be free to do that. Most novice teachers are so afraid of making a mistake that they do not feel comfortable being creative or branching out from the "cookbook" or rules of the program. That can lead to stale teaching.
I try to tell staff as I train them to teach the skill, not the materials. A curriculum is a list of skills that you want to teach your child, not a list of specific programs that are divorced from real life. You can target the same skill in a million different ways, which I think is the true message of NET. If you think of the skill, and allow yourself to see all the different ways in which that skill shows up in the environment, you open your eyes to all the teaching opportunities in the environment. I feel that if I can get staff to really understand that, they're on their way to becoming more effective teachers already.