The objectives of the study were: (1) To study the knowledge on scientific messages / aspects among the primary school teachers at the pre- study, post- study and post- post study (after 30 days) phases. (2) To study the impact of selected scientific messages / aspects through video programmes as an informal learning strategy among the primary school teachers in Periyar district. (3) To find out and compare the knowledge gain and retention of knowledge on the manipulated scientific messages / aspects through video program among the primary school teachers. (4) To find out and study the influence of the selected intervening variables such as sex, age, socio - economic status, teaching experience, mass media exposure and participation in extra curricular activities of the experimental group on knowledge at the pre - study phase, knowledge gain, retention of knowledge and loss of knowledge on scientific messages / aspects among the primary school teachers.

The hypotheses were: (1) There will be a significant mean score difference in knowledge on scientific messages / aspects between pre and post- study phases among the primary school teachers in Periyar district. (2) There will be a significant mean score difference in knowledge on scientific messages / aspects between post and post- post study (after 30 days) phases among the primary school teachers of the study. (3) There will be a significant mean score difference between the knowledge gain and retention of knowledge on scientific messages / aspects among the primary school teachers of the study. (4) There will be a significant relationship between the age and knowledge at the pre- study phase, knowledge gain, and retention of knowledge and loss of knowledge on scientific messages/aspects among the primary school teachers of the study. (5) There will be a significant relationship between the socio- economic status and knowledge at the pre - study phases, knowledge gain, and retention of knowledge and loss of knowledge on scientific messages / aspects among the primary school teachers of the study. (6) There will be a significant relationship between the teaching experience and knowledge at the pre - study phases, knowledge gain, and retention of knowledge and loss of knowledge on scientific messages/aspects among the primary school teachers of the study.

The tools used for data collection were: Individual information interview Schedule (IIIS) and Learning Assessment Schedule (LAS).

The findings of the study were: (1) The manipulation of ‘science for all’ programs through video as an informal learning has helped in gaining knowledge on scientific messages/aspects among the primary school teachers. (2) Primary school teachers retain most of the knowledge gained by them. However, there is some constant exposure or reinforcement of scientific messages is needed in order to make them retain all the knowledge gained by the primary school teaches. (3) The teachers are able to retain significant amount of knowledge acquired by the primary school teachers after the manipulation of scientific messages through the video programmes in spite of time gap between the phases. (4) Primary school teachers retain most of the knowledge gained by them. Even after a month of the study that is an indication of permanent change in cognitive behavior. (5) Sex differences do not influence the independent variables i.e. knowledge at the entry stage, knowledge gain, and retention of knowledge and loss of knowledge on scientific messages/aspects among the primary school teachers. (6) Primary school teacher’s age has no influence on knowledge gain, retention and loss of knowledge where as entry-level knowledge shows influence on the age of the primary school teachers; however the influence is relatively low. (7) The exposure to mass media has no significant impact on the knowledge at the entry level, knowledge gain, retention and loss of knowledge which may be due to the mass media programs viewed / listen / read by the teachers are not related to academic and scientific aspects and they may be treating mass media for entertainment and recreational purposes only.