ABA Fundamentals

Effects of stimulus disparity on acquisition of sight word sets: Manipulation of initial letter

Chotto et al. (2023) · Journal of Applied Behavior Analysis 2023
★ The Verdict

Spread sight words that share the same initial letter across teaching sets to cut the number of trials preschoolers need to master them.

✓ Read this if BCBAs and RBTs teaching early reading in preschool or kindergarten classrooms.
✗ Skip if Clinicians focused on non-reading skills or older learners working on comprehension.

01Research in Context

01

What this study did

Chotto et al. (2023) asked whether the first letter of sight words changes how fast kids learn.

They taught 4- to 6-year-olds two kinds of word sets. One set mixed words that start with the same letter across different lessons. The other set kept those words together.

The team used an alternating-treatments design and counted how many trials each child needed to master a set.

02

What they found

Kids mastered a set faster when words that share the same first letter were spread across lessons instead of grouped together.

Fewer trials meant less teaching time and quicker progress through the list.

03

How this fits with other research

Kupzyk et al. (2011) also used an alternating-treatments design to tweak sight-word drills. They showed that adding strategy steps to flash cards beats plain incremental rehearsal. Chotto’s work adds a new layer: the makeup of the word list itself matters.

Cubicciotti et al. (2019) looked at stimulus order and found each child learned best with a different sequence. That lines up with Chotto’s push to tailor the list, not just the procedure.

Lewis et al. (2025) made SIR easier by putting the words on one page instead of flash cards. Their goal was faster prep; Chotto’s goal was faster learning. Both studies chase efficiency but attack different parts of the teaching chain.

04

Why it matters

If you run discrete-trial sight-word lessons, split words that start with the same letter across sets. This tiny change can shave trials off mastery and keep kids moving. Try it on Monday by swapping one grouped set for a mixed set and track trial-to-criterion.

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→ Action — try this Monday

Take your next sight-word set, move any same-letter words into different sets, and run a quick trial count to see the speed-up.

02At a glance

Intervention
discrete trial training
Design
alternating treatments
Sample size
5
Population
not specified
Finding
positive
Magnitude
medium

03Original abstract

Due to the prevalence of words that cannot be read phonetically in the English language, sight word instruction is required to supplement phonics instruction. In this study, we manipulated stimulus disparity in sight word sets by comparing the effects of sets of sight words with the same initial letter (3 words per set, 3 total sets) versus distributing words with the same initial letter across sets when assessing acquisition of the combined set (9 words) for 5 children who ranged from 4-6 years of age using a combined adapted alternating treatments design and pre-posttest design. All participants mastered the 3-word sets in both teaching conditions but did not master the control sets. In general, participants required more teaching sessions when the words in sets began with the same letter. These findings are consistent with stimulus disparity research demonstrating that discrimination training is generally less efficient when comparison stimuli are similar.

Journal of Applied Behavior Analysis, 2023 · doi:10.1002/jaba.955