Effects of Teacher- Versus Application-Delivered Instruction on the Expressive Vocabulary of At-Risk Preschool Children

Abstract

A repeated acquisition (RA) design was used to compare the effectiveness of research-based instruction embedded in repeated storybook reading facilitated by an adult or tablet application (app) on the vocabulary knowledge of six preschool children. All participants selected scored below the 40th percentile on the Preschool Language Scales–Fifth Edition. Three target verbs frequently encountered in speech and text (Tier 2) from 16, age-appropriate storybooks were selected. Definitions of the target verb, multiple contextualized examples, and demonstrations of the verb action were taught. All children benefited from the intervention in both conditions, but increases were higher for four participants in the app condition, and modest for two participants in both conditions. Depth of knowledge was assessed using a scoring rubric, and four children increased their ability to provide multiple examples or a definition of the word. Implications for research and practice are discussed.

How to Be RAD: Repeated Acquisition Design Features that Enhance Internal and External Validity

“…The repeated rapid alterations in a RAD help to control for history, maturation, and other time-related confounds (Van den Noortgate & Onghena, 2007). For example, Dennis and Whalon (2020) repeatedly measured words learned in alternating interventions to examine the extent to which two different methods of intervention delivery (app-or teacherdelivered) resulted in the greatest vocabulary learning among preschoolers. As an alternative, researchers can also employ a RAD in an effectiveness study.…”

“…When there are few participants, the need to counterbalance the order of stimulus set presentation increases so that it is possible to disentangle the effect of intervention from order and stimuli. Dennis and Whalon (2020) first created a random sequence of stimulus sets for each of their interventions, app-and teacher-delivered vocabulary instruction. Because targeted stimuli were specific to conditions, participants received stimulus sets in the order that corresponded to the sequential random assignment of delivery format.…”

“…Many applied researchers use a RAD as an alternative to a MBD when an extended baseline condition is not appropriate for the study population or not practical in an applied setting (e.g., preschool). For example, Dennis and Whalon (2020) cited concern for preschoolers' fatigue as a possible artifact of adding a baseline condition. Thus, they relied on consistent replications of pre-to postintervention gains within and across participants to make causal inferences about the independent and dependent variables.…”

“…In two of the sampled studies in Table 1, researchers used random assignment. Allowing for the examination of differential effectiveness between two different instructional delivery methods on vocabulary outcomes, Dennis and Whalon (2020) randomly assigned preschoolers to start each week in app-or teacher-delivered instruction. Likewise, Sullivan et al (2013) had students select their initial fluency drill condition assignment from a deck of cards; students drew one card that had either racetrack or list printed on it.…”

“…By including the maintenance condition, they were able to measure the retention of a sample of stimuli that received intervention. In other RAD studies, researchers explored the degree to which participants' retained improvements over time by conducting a single probe of stimulus sets between 1-and 7-weeks following intervention (e.g., Dennis & Whalon, 2020;Kelley et al, 2015). Rather than assess retention of all taught words, Dennis and Whalon (2020) randomly selected vocabulary from a list of mastered words to assess at follow up.…”