There were 120 pupils in years 1 to 5 from two schools which were interviewed using specially prepared tasks to study the variety of interpretations given to letters by adolescents. Results indicate that two distinct conceptual understandings of the role played by a letter in relation to geometrical data exist in pupil's thinking. (Author/TG)

Students were measured on eleven aptitudes from Guilford's structure-of-intellect cube, and randomly assigned to symbolic or figural instructional modes for a unit on functions. Achievement was measured and compared for students with different aptitudes. (SD)