Trial Outcomes & Findings for Retrieval-Based Word Learning in Developmental Language Disorder (NCT NCT05325333)

Last Updated: 2025-08-29

Results Overview

Five 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 expanding schedule and one in which retrieval trials occurred on the standard schedule.

Recruitment status

COMPLETED

Study phase

Target enrollment

28 participants

Primary outcome timeframe

5 minutes after end of learning period

Results posted on

2025-08-29

Participant Flow

Children with DLD are recruited primarily through speech pathologists and preschool teachers. They are provided with eligibility guidelines and a parent letter. Once the parent is given the letter, they choose to contact us, if interested. Children with typical language development are recruited through advertising in preschools.

Children are initially tested to see if they meet the inclusionary and exclusionary criteria of Developmental Language Disorder. These include falling below age level on a language test, while passing a hearing screening, a non-verbal IQ test, and an autism screener. Referrals of children who do not meet all these criteria result from the fact that DLD is not readily recognizable to non-professionals (parents, preschool teachers).

Participant milestones

Participant milestones
Measure	Children With Developmental Language Disorder These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development Children whose language development is as expected for their age.
Overall Study STARTED	14	14
Overall Study COMPLETED	14	14
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Retrieval-Based Word Learning in Developmental Language Disorder

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.	Total n=28 Participants Total of all reporting groups
Age, Continuous	58 months STANDARD_DEVIATION 6.67 • n=5 Participants	58 months STANDARD_DEVIATION 7.02 • n=7 Participants	58 months STANDARD_DEVIATION 6.72 • n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants	7 Participants n=7 Participants	13 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	7 Participants n=7 Participants	15 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	12 Participants n=5 Participants	14 Participants n=7 Participants	26 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) White	11 Participants n=5 Participants	12 Participants n=7 Participants	23 Participants n=5 Participants
Race (NIH/OMB) More than one race	3 Participants n=5 Participants	2 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	14 participants n=5 Participants	14 participants n=7 Participants	28 participants n=5 Participants
Maternal education in years	16.21 years STANDARD_DEVIATION 2.67 • n=5 Participants	16.57 years STANDARD_DEVIATION 1.65 • n=7 Participants	16.39 years STANDARD_DEVIATION 2.18 • n=5 Participants

PRIMARY outcome

Timeframe: 5 minutes after end of learning period

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Expanding and Standard Retrieval Schedules at 5 Mins Expanding Schedule	3.93 number of words recalled Standard Deviation 2.70	6.43 number of words recalled Standard Deviation 1.28
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Expanding and Standard Retrieval Schedules at 5 Mins Standard Schedule	3.71 number of words recalled Standard Deviation 2.61	5.21 number of words recalled Standard Deviation 2.61

PRIMARY outcome

Timeframe: 1 week after end of learning period

One week after end of learning sessions, 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 expanding schedule and one in which retrieval trials occurred on the standard schedule.

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Expanding and Standard Retrieval Schedules at One Week Expanding schedule	3.86 number of words recalled Standard Deviation 2.63	6.00 number of words recalled Standard Deviation 1.96
Word Form Recall Accuracy (Number of Words Correctly Recalled) on Expanding and Standard Retrieval Schedules at One Week Standard schedule	3.36 number of words recalled Standard Deviation 2.87	5.57 number of words recalled Standard Deviation 2.50

PRIMARY outcome

Timeframe: 5 minutes after end of learning period

Five minutes after end of learning sessions, 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 expanding schedule and one in which retrieval trials occurred on the standard schedule.

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Expanding and Standard Retrieval Schedules at 5 Mins Expanding schedule	7.29 number of word meanings recalled Standard Deviation 1.64	7.71 number of word meanings recalled Standard Deviation 0.61
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Expanding and Standard Retrieval Schedules at 5 Mins Standard schedule	7.36 number of word meanings recalled Standard Deviation 1.91	7.21 number of word meanings recalled Standard Deviation 2.12

PRIMARY outcome

Timeframe: 1 week after end of learning period

One week after end of learning sessions, 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 expanding schedule and one in which retrieval trials occurred on the standard schedule.

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Expanding and Standard Retrieval Schedules at One Week Expanding schedule	7.00 number of word meanings recalled Standard Deviation 2.00	7.21 number of word meanings recalled Standard Deviation 1.25
Word Meaning Recall Accuracy (Number of Semantic Associations Correctly Recalled) on Expanding and Standard Retrieval Schedules at One Week Standard schedule	6.57 number of word meanings recalled Standard Deviation 2.10	7.29 number of word meanings recalled Standard Deviation 2.16

PRIMARY outcome

Timeframe: 1 week after end of learning period

Upon hearing a novel word, the child is asked to indicate (by pointing) which picture among 4 options is referred to; for words learned under the Expanding condition.

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Word Recognition (Number of Words Accurately Identified) on Expanding Condition and Standard Retrieval Schedules Expanding schedule	7.36 pictures correctly identified with word Standard Error 1.01	7.93 pictures correctly identified with word Standard Error 0.27
Word Recognition (Number of Words Accurately Identified) on Expanding Condition and Standard Retrieval Schedules Standard Schedule	6.43 pictures correctly identified with word Standard Error 1.91	7.79 pictures correctly identified with word Standard Error 0.58

SECONDARY outcome

Timeframe: Test completed at start of study

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 between 85 and 115 (1 SD above and below the mean of 100) are interpreted as reflecting receptive vocabulary levels expected for age.

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Peabody Picture Vocabulary Test - Fifth Edition	95.36 score on a scale Standard Deviation 13.89	124.43 score on a scale Standard Deviation 12.49

SECONDARY outcome

Timeframe: Information collected at start of study

Educational attainment of child's mother in terms of years of education

Outcome measures

Outcome measures
Measure	Children With Developmental Language Disorder n=14 Participants These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.	Children With Typical Language Development n=14 Participants Children whose language development is as expected for their age.
Maternal Education in Years	16.21 Years Standard Deviation 2.67	16.57 Years Standard Deviation 1.65

Adverse Events

Children With Developmental Language Disorder

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Children With Typical Language Development

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Patricia Deevy, Research Associate

Purdue University

Phone: 765-496-1821

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place