Effect of Phonotactic Probability and Orthography on Vocabulary Learning (VOCAB+)

May 14, 2026 updated by: Mariana Silva, Arizona State University

The Effect of Phonotactic Probability and Orthography on Vocabulary Learning

The purpose of the study is to investigate how phonotactic probability) and orthography affect vocabulary by children with low oral language levels. The investigators will use a 2 x 2 within-subjects factorial design where every participant receives the treatment. This 12-week study aims to improve vocabulary learning efficiency for children with low oral language levels. The study's findings will uniquely contribute to the field in that this is the first research study using real words instead of nonwords while combining word learning research with vocabulary learning.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The investigators are proposing a vocabulary intervention that analyzes word sounds and sound segments. This analysis offers valuable insights into how children at risk for specific learning disabilities, such as dyslexia, DLD or speech and language impairments, learn words differently from typically developing children.

Study Type

Interventional

Enrollment (Actual)

23

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85013
        • Osborn District School Encanto

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

Enrolled in or just completed third grade.

Exclusion Criteria:

Any diagnosis of sensory impairments A diagnosis of autism or traumatic brain injury

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Single group Assignment
There are no subgroups in this study. All participants will receive the intervention.
Behavioral: VOCAB +

The purpose of the study is to investigate how phonotactic probability and orthography effect vocabulary learning by children with low oral language levels. We will be using a 2 x 2 within-subjects factorial design where every participant serves as their own control. This 12-week study aims to improve the efficiency of vocabulary learning for children with low oral language levels.

The four interventions that are all participants will be exposed to are the following: high pp words with orthography; high pp words without orthography; low pp words with orthography; low pp words without orthography.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
1. Vocabulary Production 2. Vocabulary Recognition 3. Vocabulary Comprehension 4. Spelling
Time Frame: up to 12 weeks

  1. Production Number of correctly produced target words (range 0-32), measured using a picture-naming task, scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Posttest (Weeks 11-12)

  2. Recognition Number of correctly identified target words from a 4-choice array (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Posttest (Weeks 11-12)

  3. Comprehension Number of correctly selected target images from a 4-option array (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Posttest (Weeks 11-12)

  4. Spelling Number of correctly spelled target words (range 0-32), measured using a dictated spelling task, scored as correct (1) or incorrect (0), and reported as percentage correct.

Time Frame Posttest (Weeks 11-12)
up to 12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
1. Learning Change Vocabulary Production 2. Learning Change Vocabulary Recognition 3. Learning Change Vocabulary Comprehension 4. Learning Change Vocabulary Spelling
Time Frame: up to 12 weeks

  1. Production Change in the number of correctly produced target words (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct, measured at baseline and posttest.

    Time Frame Baseline (Weeks 1-2) to Posttest (Weeks 11-12)

  2. Recognition Change in the number of correctly identified target words (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct, measured at baseline and posttest.

    Time Frame Baseline (Weeks 1-2) to Posttest (Weeks 11-12)

  3. Comprehension Change in the number of correctly selected target images (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct, measured at baseline and posttest.

    Time Frame Baseline (Weeks 1-2) to Posttest (Weeks 11-12)

  4. Spelling Description Change in the number of correctly spelled target words (range 0-32), scored as correct (1) or incorrect (0), and reported as percentage correct, measured at baseline and posttest.(Weeks 1-2) to Posttest
up to 12 weeks
1. Daily Vocabulary Production 2. Daily Vocabulary Recognition 3. Daily Vocabulary Comprehension 4.Daily Vocabulary Spelling
Time Frame: Weeks 3-10

  1. Production Number of correctly produced target words per session (range 0-4), measured using a picture-naming task, scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Four times per week during the intervention period (Weeks 3-10)

  2. Recognition Number of correctly identified target words per session from a 4-choice array (range 0-4), scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Four times per week during the intervention period (Weeks 3-10)

  3. Comprehension Number of correctly selected target images per session from a 4-option array (range 0-4), scored as correct (1) or incorrect (0), and reported as percentage correct.

    Time Frame Four times per week during the intervention period (Weeks 3-10)

  4. Spelling Number of correctly spelled target words per session (range 0-4), scored as correct (1) or incorrect (0), and reported as percentage correct.

Time Frame four times per week during the intervention
Weeks 3-10

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total number of words learned to criterion
Time Frame: 12 weeks
Is there a significant difference in the total number of words learned to criterion comprehension, recognition, production, spelling recognition, and spelling production?
12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Arizona State University

Collaborators

Arizona State University
The Child Language and Literacy Lab (CHILLL)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 3, 2025

Primary Completion (Actual)

April 25, 2025

Study Completion (Actual)

April 25, 2025

Study Registration Dates

First Submitted

December 17, 2024

First Submitted That Met QC Criteria

April 12, 2025

First Posted (Actual)

April 20, 2025

Study Record Updates

Last Update Posted (Actual)

May 18, 2026

Last Update Submitted That Met QC Criteria

May 14, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00020728

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

  • Study Protocol
  • Statistical Analysis Plan (SAP)
  • Informed Consent Form
  • Clinical Study Report

IPD Sharing Time Frame

The data will be made available within 7 months of the study's conclusion and will remain available for at least 5 years.

IPD Sharing Access Criteria

Signing a data use agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Study Data/Documents

  1. Study Protocol
    Information comments: signing a data agreement

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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