The objectives of the study were:  (1) To determine the comparative effectiveness of three intervention strategies in the learning of Hindi language by class IX students i.e. Advance Organizer Model (AOM), Piaget’s Cognitive Maturity Model (PCMM) and Conventional Teaching (CT) as reflected in their achievement and retention at knowledge (K), understanding (U), application (A) and total (T) levels. (2) To determine the comparative effectiveness of three intervention strategies for the enhancement and retention of cognitive maturity of students of class IX. (3) To study the interactive effect of intelligence with each of the intervention strategies i.e. AOM, PCMM and CT in determining the achievement level of students in Hindi language. (4) To study the interactive effect of personality with each of the intervention strategies i.e. AOM, PCMM and CT in determining the achievement level of students in Hindi language.

The  hypotheses of the study were: (1) There will be significant difference in the level of achievement in Hindi language in respect of students of class IX taught through AOM, PCMM and CT when knowledge, understanding, application and total level scores of students separately on achievement test are compared. (2) There will be significant difference in the retention level in Hindi language in respect of students of class IX taught through AOM, PCMM and CT when knowledge understanding, application and total level scores of students on retention test are compared. (3) There will be significant interaction effect separately between the three treatment levels and the four achievement levels, the three treatment levels and the five CMT level. (4) There will be significant difference in the gains in level of cognitive maturity of students being taught using AOM, PCMM and CT when their scores on cognitive maturity test are compared. (5) There will be significant difference in the retention level of cognitive maturity of students being taught using AOM, PCMM and CT when their scores on cognitive maturity test are compared. (6) There will be statistically significantly difference separately in the knowledge, understanding, application and total level scores in Hindi language of students scoring above average in intelligence and taught by AOM, PCMM and CT. (7) There will be statistically significantly difference separately in the knowledge, understanding, application and total level scores in Hindi language of students scoring below average in intelligence and taught by AOM, PCMM and CT separately. (8) There will be statistically significant difference separately in the knowledge, understanding, application and total levels retention scores in Hindi language of students scoring above average in intelligence and taught by AOM, PCMM and CT. (9) There will be statistically significant difference separately in the knowledge (K), understanding (U), application (A) and total (T) levels retention scores in Hindi language of students scoring below average in intelligence and taught by AOM, PCMM and CT. (10) There will be statistically significant difference in the K, U, A and T levels scores in Hindi language of students scoring above average on personality questionnaire and taught by AOM, PCMM and CT. (11) There will be statistically significant difference in the K, U, A and T levels scores in Hindi language of students scoring below average on personality questionnaire and taught by AOM, PCMM and CT.

Experimental Group I treated with PCMM; experimental group II was taught with AOM and the control group through CM. The duration of treatment was 120 working days. 113 students of class IX from Government Central Girls Senior Secondary School, Ajmer City were selected as a sample by random sampling method.

The Group General Mental Ability Test (GMAT) by S. Jalota, HSPQ by Kapoor and Mehrotra, Hindi Language Achievement Test (HLAT) (Split-half reliability coefficient =0.80) and Cognitive Maturity Test were developed by researcher for data collection.

The data were analyzed by ANOVA and ANCOVA.

The findings of the study were: (1) AOM and PCMM enhanced Hindi language achievement scores on HLAT of students at Application level than CTM. However effects of the AOM, PCMM and CTM did not differ significantly for achievement at Knowledge, Understanding & Total attainment levels. (2) AOM enhanced retention scores of students on HLAT of Application and Total attainment levels more than PCMM and CTM, whereas for Knowledge and Understanding levels retention effect of the experimental groups I and II and control group treatment did not differ significantly. (3) Interaction of AOM, PCMM and CT with various levels of achievement revealed that AOM was more effective for retention at Total level than Knowledge, Understanding and Application levels, whereas PCMM proved to be more effective for retention at Understanding & Total levels than Knowledge and Application levels. CT was more effective for retention at Knowledge and Application levels than Understanding and Total levels. (4) AOM proved more effective than CM at all the five cognitive maturity tasks. (5) Interaction of AOM, PCMM and CT with various levels of cognitive maturity revealed that PCMM was more effective for retention for CMT (Total), whereas AOM was more effective for retention at Tasks I and II and CMT (total) conventional teaching method proved effective for retention for tasks I, II, III and IV. (6) Personality traits interacted maximally with model approaches were B, C, and Q3 and those which interacted minimally with model approaches were factors A, D, E, I, J, Q2 and Q4.