Six participants participated in the current research with five of the participants demonstrating mastery of letter sounds throughout conditions and one participant demonstrating echoic and tact behavior only during teaching trials. During baseline conditions three participants demonstrated mastery of 10 targets. During treatment conditions five participants mastered 43 targets. The lead investigator conducted all session probes. Interobserver agreement was conducted in 61.88% of all sessions, agreement was observed in 84.92% of trials. Figures 1–3 are displayed below for visual analysis.
Participant 1 began participation in the current research with a score of 113 on the VB-MAPP and demonstrated nine and a half milestones in tact and nine milestones in echoic behavior. When assessed using the Core Phonics Survey, they earned a score as a Strategic learner (60); they demonstrated mastery of 26 uppercase letter symbol names, 25 lower case letter symbol names, four consonant sounds, and zero short vowel sounds. Participant 1 began baseline conditions with prior mastery of four letter sounds. During the initial baseline condition Participant 1 mastered two targetsthrough Progressive Phonics, they mastered the first sound after five sessions and mastered the second sound after eight sessions. Within the first intervention condition Participant 1 mastered four additional targets after five sessions. Participant 1 was introduced to four additional targets and demonstrated mastery of two additional sounds at session ten. Participant 1 returned to baseline and demonstrated mastery of two of the targets at the fifth session of the condition. In the second intervention condition Participant 1 mastered three targets, one letter sound and two consonant blends at the fifth session of the condition. A fourth targeted consonant blend during the sixth session and three additional targeted consonant blends at the tenth session of the condition.
Participant 2 began participation in the current research with a score of 64 on the VB-MAPP and demonstrated six milestones in tact and seven and a half milestones in echoic behavior. When assessed using the Core Phonics Survey, they earned a score as an Intensive learner (46); they demonstrated mastery of 17 uppercase letter symbol names, 21 lower case letter symbol names, six consonant sounds, and zero short vowel sounds. Participant 2 began baseline conditions with prior mastery of six letter sounds. During the initial baseline condition Participant 2 did not demonstrate mastery of target through Progressive Phonics. Within the first intervention condition Participant 2 mastered one target after 10 sessions. Participant 2 returned to baseline and did not demonstrate mastery of targets. In the second intervention condition Participant 2 mastered two targets during the ninth session of the condition. It was determined that the participant would not reach the mastery criteria for the remaining two targets during a tenth session; therefore, the ninth session was the final session.
Participant 3 began participation in the current research with a score of 127 on VB-MAPP and demonstrated ten milestones in tact and echoic behavior. When assessed using the Core Phonics Survey, they earned a score as a Strategic learner (60); they demonstrated mastery of 26 uppercase letter symbol names, 26 lower case letter symbol names, zero consonant sounds, and five short vowel sounds. Participant 3 began baseline conditions with prior mastery of five letter sounds. During the initial baseline condition Participant 3 did not demonstrate mastery of targets. Within the first intervention condition Participant 3 mastered four targets after ten sessions. Participant 3 returned to baseline and demonstrated mastery of four targets at the fifth session of the condition. In the second intervention condition Participant 3 mastered four targets at the fifth session of the condition. Two targeted consonant blends during the sixth session three additional targeted consonant blends at the tenth session of the condition.
Participant 4 began participation in the current research with a score of 103.5 on the VB-MAPP and demonstrated nine milestones in tact and echoic behavior. When assessed using the Core Phonics Survey, they earned a score as an Intensive learner (55); they demonstrated mastery of 21 uppercase letter symbol names, 17 lower case letter symbol names, 10 consonant sounds, and four short vowel sounds. Participant 4 began baseline conditions with prior mastery of 10 letter sounds. During the initial baseline condition Participant 4 mastered two targets through Progressive Phonics, they mastered the first sound after five sessions, mastered the second sound after six sessions, and mastered the third sound after ten sessions. Within the first intervention condition Participant 4 mastered two targets after five sessions. Participant 4 was then introduced to two additional targets and demonstrated mastery of two additional sounds at session ten. Participant 4 returned to baseline and demonstrated mastery of one target at the fifth session of the condition. In the second intervention condition Participant 4 mastered two targets, one letter sound and one consonant blends at the fifth session of the condition. A third targeted consonant blend during the sixth session two additional targeted consonant blends at the tenth session of the condition.
Participant 5 began participation in the current research with a score of 78 on the VB-MAPP and demonstrated eight milestones in tact and eight and a half milestones in echoic behavior. When assessed using the Core Phonics Survey, they earned a score as an Intensive learner (10); they demonstrated mastery of five uppercase letter symbol names, five lower case letter symbol names, zero consonant sounds, and zero short vowel sounds. Participant 5 began baseline conditions without prior mastery of letter sounds. During the initial baseline condition Participant 5 did not demonstrate mastery of any targets. Within the first intervention condition Participant 5 mastered one target after ten sessions. Participant 5 did not demonstrate mastery of targets when they returned to baseline. In the second intervention condition Participant 5 mastered two targets ninth session of the condition. Due to Participant 5 demonstrating mastery of two targets during the ninth session, it was determined that the participant would not benefit from a tenth instructional session.
Participant 6 began participation in the current research with a score of 48.5 on the VB-MAPP and demonstrated six and a half milestones in tact and one and a half milestones in echoic behavior. When assessed using the Core Phonics Survey, they earned a score as an Intensive learner (51); they demonstrated mastery of 26 uppercase letter symbol names, 25 lower case letter symbol names, zero consonant sounds, and zero short vowel sounds. Participant 6 began baseline conditions with prior mastery of zero letter sounds. Throughout baseline and intervention conditions, Participant 6 did not demonstrate mastery of targeted letter sounds through probes; however, they demonstrated a reduction in the magnitude of prompts required to engage in desired behavior during intervention conditions. Participant 6 did not demonstrate the same reduction in the magnitude of prompts required to engage in desired behaviors during baseline conditions.