An interventional study of Retrieval-based word learning: Standard retrieval practice schedule and Retrieval-based word learning: Adaptive retrieval practice schedule in Developmental Language Disorder, Specific Language Impairment and Language Development, sponsored by Purdue University. Terminated at 1 site in United States. Open to participants aged 48 Months to 71 Months, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Purdue University · Not applicable, Interventional, and Basic science
Children with developmental language disorder (DLD; also referred to as specific language impairment) experience a significant deficit in language ability that is longstanding and harmful to the children's academic, social, and eventual economic wellbeing. Word learning is one of the principal weaknesses in these children. This project focuses on the word learning abilities of four- and five-year-old children with DLD. The goal of the project is to determine whether special benefits accrue when these children must frequently recall newly introduced words during the course of learning. In the current study, the investigators compare a "standard" repeated spaced retrieval schedule, with fixed spacing between hearing a word and attempting to retrieve it, to an "adaptive" repeated spaced retrieval schedule in which opportunities to retrieve a given word are tailored to the individual child's current knowledge state. The goal of the study is to determine whether the adaptive schedule can increase children's absolute levels of learning while maintaining the advantages of repeated spaced retrieval.
Developmental Language Disorder (DLD) affects language learning in an estimated 7% of children. Although much of the research literature has emphasized difficulties learning grammar, children with DLD also have major deficits in vocabulary. In recent work, the investigators have been examining the benefit of retrieval practice to enhance word learning and retention in preschoolers with DLD. The rationale behind this work is grounded in the growing literature in the field of cognitive psychology which shows that repeated practice in retrieving information results in greater long-term retention than continuous study of that information without opportunities for retrieval. In addition, retrieval practice that occurs after a delay-or "spacing" between study of a word and subsequent recall attempts-can lead to stronger effects.
Despite the growing evidence that repeated spaced retrieval (RSR) results in greater word learning for preschoolers with DLD, much remains to be learned. One important question concerns the absolute level of learning achieved through RSR. These investigators have found that, in the more optimal condition of RSR, these children's ability to recall new word forms (i.e., recall the phonetic form of the word such as /pobɪk/) is still low, despite being higher than recall in the comparison conditions. The main obstacle appeared to be initial word form encoding during the learning period. Longer-term retention was less of a problem, i.e., those words children could recall immediately after the learning period were also recalled one week later. In the current study, the investigators seek to improve word form recall through modifications that may improve this initial encoding. The principal means by which this study will attempt to improve encoding and, as a result, subsequent recall, is through an adaptive retrieval schedule, described below.
Sixteen children with DLD will be recruited for this study along with 16 children with typical language development (TD) matched on chronological age. Using a within-subjects design, children will learn eight novel verbs, four at a time. Each set of four will be learned over two consecutive days, with one block of four in the standard RSR condition and the other block in the adaptive RSR condition. The referents for these novel words will be photos of unfamiliar plants and animals, presented on a laptop screen. Recall of word forms and meanings will be tested 5 minutes after the learning session on the second day, and again one week later. After the one-week recall testing, a picture-pointing recognition task will also be completed.
In both conditions, children will initially hear the word paired with a photo (Study trial: This is a nepp. It's a nepp. A nepp likes rain.), immediately be asked to recall the word (Retrieval trial: What's this called?), and then see/hear it again (Study trial: This is a nepp. It's a nepp. A nepp likes rain.). After three other words are presented, the children will be asked to recall the original word (nepp) again (What's this called? What does it like?); this retrieval trial is followed by a study or "feedback" trial (This is a nepp. It's a nepp. A nepp likes rain.). The "3" spaced retrieval schedule will continue for the rest of the learning session. The difference between conditions is this: in the adaptive condition, if the child is unsuccessful in retrieving the word form, whether on the initial trial or on one of the "3" spaced trials, the subsequent study/feedback trial will be followed by an additional immediate retrieval trial for that word. If, on the other hand the child retrieves the word form successfully, the next retrieval - study sequence will appear after three intervening words. In the standard condition, an unsuccessful recall attempt will be followed by a study trial but there will be no additional immediate retrieval opportunity. Note that while children will also be asked to retrieve the word meaning (what it likes), unsuccessful recall of this information will not trigger an additional immediate retrieval opportunity. This is based on previous findings showing that the real difficulty for children with DLD is recalling the phonetic form of words, rather than meaning information.
The investigators predict that the strategic placement of additional immediate retrieval trials after incorrect spaced retrieval trials in the adaptive condition will increase the likelihood of the child's success on the next spaced retrieval trial. Findings show that spaced retrieval needs to be successful in order to build strength and promote long-term retention. With the boost to encoding provided by the immediate retrieval trial for words the child is having difficulty remembering, the word form may be more firmly encoded and more likely to be recalled on the spaced retrieval trials. This should lead to higher absolute levels of word learning in the adaptive condition compared to the standard condition.
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This study's enrollment of 7 is below the median of 71 across 100 interventional studies indexed under Language Development Disorders.
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Exclusion Criteria:
These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.
Behavioral: Retrieval-based word learning: Standard retrieval practice schedule · Behavioral: Retrieval-based word learning: Adaptive retrieval practice schedule
Children whose language development is as expected for their age.
Behavioral: Retrieval-based word learning: Standard retrieval practice schedule · Behavioral: Retrieval-based word learning: Adaptive retrieval practice schedule
Novel nouns and their meanings are practiced on 2 consecutive days. At the beginning of each learning session, a retrieval trial will immediately follow hearing the word and what it likes (a study trial). In the standard condition, the remaining retrieval trials for each word will be spaced - occurring only after 3 other words have intervened. This practice schedule is repeated the next day (Day 2).
Novel nouns and their meanings are practiced on 2 consecutive days. At the beginning of each learning session, a retrieval trial will immediately follow hearing the word and what it likes (a study trial). For the remainder of the session, there will be spaced retrieval trials for each word - occurring after 3 words have intervened. In the Adaptive condition, children will have additional retrieval opportunities throughout. These will be provided whenever the child does not remember the word form, whether it is an immediate (initial) or space retrieval trial. This practice schedule is repeated the next day (Day 2).
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Adaptive and Standard Retrieval Schedules at 5 Mins
5 minutes after second learning session, child is asked to recall and say the word associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
Time frame: 5 minutes after end of learning period
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Adaptive and Standard Retrieval Schedules at 1 Week
1 week after second learning session, child is asked to recall and say the word associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on adaptive schedule and one in which retrieval trials occurred on the standard schedule.
Time frame: 1 week after end of learning period
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Adaptive and Standard Retrieval Schedules at 5 Mins
5 minutes after second learning session, child is asked to recall and say the semantic information associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
Time frame: 5 minutes after end of learning period
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Adaptive and Standard Retrieval Schedules at 1 Week
1 week after second learning session, child is asked to recall and say the semantic information associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
Time frame: 1 week after end of learning period
Word Recognition (Number of Words Accurately Identified) on on Adaptive and Standard Retrieval Schedules
Upon hearing a novel word, the child is asked to indicate (by pointing) which picture among 4 options is referred to; for words learned on the adaptive condition and for words learned on the standard condition.
Time frame: 1 week after end of learning period
Peabody Picture Vocabulary Test, Fifth Edition
The Peabody Picture Vocabulary is an individually administered, norm-reference test that assesses receptive vocabulary for children and adults ages 2 years 6 months to 90 years and older. Standard scores are derived from number correct. Standard scores can range from a minimum of 40 and 160. Standard scores between 85 and 115 (1 standard deviation above and below the mean of 100) are interpreted as reflecting receptive vocabulary levels expected for age. Scores below 85 are interpreted as reflecting receptive vocabulary levels below what is expected for age.Scores above 115 are interpreted as reflecting receptive vocabulary levels above what is expected for age.
Time frame: at enrollment
Years of Maternal Education
Primary care-giver provides information regarding highest academic degree attained, converted to years of education
Time frame: at enrollment
| Milestone | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Started | 0 | 7 |
| Completed | 0 | 7 |
| Not completed | 0 | 0 |
5 minutes after second learning session, child is asked to recall and say the word associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
| number of words correctly recalled | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Standard | — | 4.71 ± 0.78 |
| Adaptive | — | 5.43 ± 0.37 |
1 week after second learning session, child is asked to recall and say the word associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on adaptive schedule and one in which retrieval trials occurred on the standard schedule.
| number of words correctly recalled | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Standard | — | 5.43 ± 0.75 |
| Adaptive | — | 6.43 ± 0.61 |
5 minutes after second learning session, child is asked to recall and say the semantic information associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
| number of meanings correctly recalled | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Standard | — | 8.00 ± 0.00 |
| Adaptive | — | 7.57 ± 0.79 |
1 week after second learning session, child is asked to recall and say the semantic information associated with each novel referent learned under one of two conditions: one in which retrieval trials occurred on an adaptive schedule and one in which retrieval trials occurred on the standard schedule.
| number of word meanings correctly recall | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Standard | — | 7.86 ± 0.38 |
| Adaptive | — | 7.43 ± 0.98 |
Upon hearing a novel word, the child is asked to indicate (by pointing) which picture among 4 options is referred to; for words learned on the adaptive condition and for words learned on the standard condition.
| number of referents correctly recognized | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Standard | — | 7.29 ± 0.29 |
| Adaptive | — | 7.86 ± 0.14 |
The Peabody Picture Vocabulary is an individually administered, norm-reference test that assesses receptive vocabulary for children and adults ages 2 years 6 months to 90 years and older. Standard scores are derived from number correct. Standard scores can range from a minimum of 40 and 160. Standard scores between 85 and 115 (1 standard deviation above and below the mean of 100) are interpreted as reflecting receptive vocabulary levels expected for age. Scores below 85 are interpreted as reflecting receptive vocabulary levels below what is expected for age.Scores above 115 are interpreted as reflecting receptive vocabulary levels above what is expected for age.
| score on a scale | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Peabody Picture Vocabulary Test, Fifth Edition | — | 113.71 ± 13.33 |
Primary care-giver provides information regarding highest academic degree attained, converted to years of education
| years | Children With Developmental Language Disorder | Children With Typical Language Development |
|---|---|---|
| Years of Maternal Education | — | 16.14 ± 3.08 |
Collected over 4 weeks. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Children With Developmental Language Disorder | — | — | — |
| Children With Typical Language Development | 0/7 (0%) | 0/7 (0%) | 0/7 (0%) |
Trial terminated before DLD group was recruited due to a change in study priorities. A related study took precedence and was prioritized for completion, making continuation of this study unfeasible.
| Age, Continuous(months) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| Mean | — | 55 ± 4.12 | 55 ± 4.12 |
| Sex: Female, Male(Participants) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| Female | — | 2 | 2 |
| Male | — | 5 | 5 |
| Ethnicity (NIH/OMB)(Participants) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| Hispanic or Latino | — | 0 | 0 |
| Not Hispanic or Latino | — | 7 | 7 |
| Unknown or Not Reported | — | 0 | 0 |
| Race (NIH/OMB)(Participants) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| American Indian or Alaska Native | — | 0 | 0 |
| Asian | — | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | — | 0 | 0 |
| Black or African American | — | 0 | 0 |
| White | — | 7 | 7 |
| More than one race | — | 0 | 0 |
| Unknown or Not Reported | — | 0 | 0 |
| Region of Enrollment(participants) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| United States | — | 7 | 7 |
| Maternal Education(years) | Children With Developmental Language Disorder | Children With Typical Language Development | Total |
|---|---|---|---|
| Mean | — | 16.14 ± 3.08 | 16.14 ± 3.08 |
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