The Effect of Various High-Probability to Low-Probability Instruction Ratios During the Use of the High-Probability Instructional Sequence.
Five easy tasks to one hard task is the best ratio for the high-p sequence.
01Research in Context
What this study did
Ertel et al. (2019) asked which high-p to low-p ratio works best. They tried 3:1, 5:1, and 10:1. Three children with autism took part. The team used an alternating-treatments design. Each session mixed the ratios so the child never knew which was coming.
What they found
The 5:1 ratio won. Two of the three kids followed directions most often after five easy tasks then one hard task. The 3:1 ratio helped a little. The 10:1 ratio added extra work with no extra payoff.
How this fits with other research
Whitehead et al. (1975) saw the same sweet spot years earlier. They taught picture names to children with ID using fixed-ratio schedules. Ratios in the middle, around 3-5, beat both lower and higher ones.
Whitehouse et al. (2014) used the same alternating-treatments setup with kids with autism. They compared massed, distributed, and mixed tact trials. Like Hallie, they found that packing more trials together gave faster learning.
The line of studies shows ABA keeps finding the same rule: medium density beats sparse or crammed.
Why it matters
Next time you run a high-p sequence, start with 5:1. Count five quick, easy responses before you present the target instruction. If compliance dips, do not pile on more high-p tasks; stick with five. This ratio saves time and keeps the child engaged.
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02At a glance
03Original abstract
The high-probability (high-p) instructional sequence, which involves the delivery of a series of high-p instructions immediately before delivery of a low-probability (low-p) instruction, is a commonly used procedure to increase compliance among children and individuals with intellectual disabilities. Although the modal ratio of high-p instructions to low-p instructions is 3:1, other ratios may be more effective. In the current study, we compared three ratios of high-p with low-p instructions (i.e., 1:1, 3:1, and 5:1) during use of the high-p instructional sequence to increase compliance among three children with autism. Results suggest that the high-p sequence was effective to increase compliance for two of three participants and that the 5:1 ratio was most effective overall, although differences among ratios were slight for some participants. Implications of these findings and directions for future research are discussed.
Behavior modification, 2019 · doi:10.1177/0145445518782396