Mass trialing (presenting 10, 20, or some other number of consecutive trials on the same target) is not often used in ABA/VB. The preferred procedure is to mix and vary different targets and tasks. This means that we will switch among mands, tacts, intraverbals, receptive ID, RFFC (receptive by feature, function, class), TFFC (tact by FFC), motor imitation, echoics, etc. This makes "autipilot" (my affectionate term for the tendency of kids with autism to respond rotely once they've "figured out" what you want them to do) impossible, since the child cannot simply respond identically 10, 20, or however many times in a row without actually attending, discriminating, and learning.
One of the most common complaints about errorless learning (EL) is that it "makes children prompt dependent." This can be true if the teacher doesn't properly fade the prompts. Transfer trials, in which prompts are immediately faded to allow for independent responses, are critical to success with EL. Rather than following a set prompt level to criterion, it is preferable to use most-to-least prompting and adjust your prompting moment-to-moment according to the child's responses. A good rule of thumb to follow is that for every prompted trial you run, immediately run an unprompted, or transfer, trial. This procedure looks like this:
Teacher: "What is it? Cookie. (echoic prompt)"
Teacher: "Right. What is it? (no echoic prompt)"
Child: "Cookie." (Teacher immediately reinforces.)
You can see that the initial prompted trial was not reinforced, while the unprompted/transfer trial was. This differentially reinforces independent responding, which increases the probability that the child will respond before or without the prompt. This also prevents prompt dependency by making the prompt (which delays reinforcement) slightly aversive.
Children need to be able to respond not only accurately, but quickly as well. Very few behaviors are truly functional when they occur with a long delay after the antecedent. Imagine asking someone you're meeting for the first time for their name and having them reply 10 seconds later. To be truly "mastered" and functional, behaviors need to have both accuracy and speed. This is teaching to fluency and is crucial for skills to be successfully acquired, retained, and generalized. To achieve fluency in teaching, the teacher needs to control for two variables: Latency and intertrial intervals. Latency is the time between the end of the antecedent and the beginning of the child's response. There should rarely, if ever, be a latency of longer than 2 or 3 seconds. The way to control for latency is with errorless learning. If the child does not begin to respond within those 2-3 seconds, the teacher should prompt, reinforce, and run the transfer trial. By prompting when necessary, you can keep latencies short and reinforce faster, independent responses. In addition to short latencies, you also want short intertrial intervals (ITIs). ITIs are the time between the end of the consequence for one trial and the beginning of the next antecedent. This can also be referred to as rate of teaching, since this variable is purely related to the teacher. Again, ITIs of no more than 2-3 seconds are preferable. Short ITIs allow for more teaching to be done in less time and keeps motivation to work high and motivation to escape or stim low.