McIlwaine, William B2016-07-082016-07-0819531953b1479326xhttps://hdl.handle.net/2144/16914Thesis (M.A.)--Boston UniversityThe problem of this investigation was to establish three a test re-test technique a learning index of the scientific principle, "Molecular Motion Varies with Temperature". This learning index will indicate the approximate mental age level at which this princfiple can be taught effectively to children of similar ability and background. A review of the literature established that the teaching of principles is an effective method for teaching science. After selecting the principle seven demonstrations were devised to illustrate the principle as completely as possible. In devising the demonstrations the author tried to make them simple, infallible, and dynamic. The time allotted for this material was approximately 15 minutes. [TRUNCATED]en-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictions.Thesis/Dissertation