Evaluating tact instruction in two languages for bilingual children with autism spectrum disorder
Teach tacts in both languages side-by-side; waiting to add the second language slows learning.
01Research in Context
What this study did
Zhao et al. (2026) asked: Should we teach new tacts in both languages at once, or one language first? They used an alternating-treatments design with bilingual children with autism.
Each child got three setups: simultaneous (English and Spanish words together), sequential (English first, Spanish later), and monolingual (English only). The team tracked how fast the kids learned to name pictures correctly.
What they found
Simultaneous bilingual instruction beat sequential. Kids reached mastery faster when both language labels were taught side-by-side.
Surprise: English-only lessons were the speediest of all. Any bilingual plan took extra trials, but simultaneous was the least slow.
How this fits with other research
The pattern copies Davison et al. (1989) and Rosenthal et al. (1980). Those teams also found that presenting items together—called concurrent or simultaneous—beats teaching one at a time or in isolation.
Whitehouse et al. (2014) looked at massed versus spread-out tact trials for kids with autism. Like Zhao, they used an alternating-treatments design and tracked tact mastery. Both studies show that how you arrange trials matters as much as what you teach.
No clash here: earlier work used only one language, so they could not spot the extra load bilingual learning adds. Zhao extends the old rule—concurrent is better—into bilingual territory.
Why it matters
If you serve bilingual families, start both languages together. Sequential plans drag out acquisition and still need extra steps to untangle the labels later. When speed is key, pick one language first, then add the second after mastery. Either way, avoid long gaps between languages—it only creates more work for you and the child.
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02At a glance
03Original abstract
Bilingual individuals can acquire two languages simultaneously or sequentially. Study 1 examined the effects of simultaneous instruction (introducing tacts in both languages at the same time) and sequential instruction (introducing tacts in English, followed by a second language after mastery) with four children with autism. Both instructional procedures were effective, but simultaneous instruction promoted better conditional discriminations between the two languages than sequential instruction. Study 2 compared monolingual with bilingual (sequential) instruction with three participants. Teaching tacts in a single language was substantially more efficient than teaching tacts in two languages for all participants. As in Study 1, participants required additional simultaneous teaching after mastering sequentially taught targets to establish conditional discriminations, whereas monolingual instruction required no additional teaching. These results indicate that monolingual instruction is more efficient than sequential bilingual instruction, although sequential bilingual teaching can still be effective. The findings have important implications for designing bilingual instruction.
Journal of Applied Behavior Analysis, 2026 · doi:10.1002/jaba.70058