This study examined the effects of an advance organizer and background experience in science on the attainment of science concepts. Ninth-grade earth science students (N=90) were given the Dubbins Earth Science Test (DEST) and a Science Background Experience Inventory (SBEI) developed by the author. They were then placed into high, medium, and low experience groups, each group subdivided into a treatment (receiving an advance organizer on the rock cycle) and a control (receiving a placebo on the rock cycle) group. A DEST posttest was given after two weeks; in addition, data on sex, Differential Aptitude Test (DAT) scores, socioeconomic status, and grade point average were collected. It was concluded that: (1) neither the advance organizer nor the background experience of the student made a significant difference in achievement; (2) there was no significant interaction between method and background experience of the student; (3) there was a strong covariance relationship between the DAT section on Abstract Reasoning and achievement on the DEST. Interpretations include, among others, the possibility that the unit of study may not have been broad enough to allow for a maximum advance organizer effect and that the sample did not include the full spectrum of student abilities. (Author/JN)