THE RELATIONSHIPS BETWEEN AUDITORY AND VISUAL FUNCTIONING AND READING ACHIEVEMENT WERE EXPLORED. AN ADDITIONAL OBJECTIVE WAS TO INVESTIGATE THE INFLUENCE OF DEVELOPMENTAL FACTORS ON THESE VARIABLES. A WIDE RANGE OF AUDITORY AND VISUAL SKILLS WAS SAMPLED IN POOR AND NORMAL READERS AT THREE DIFFERENT GRADE LEVELS (FIRST, THIRD, AND FIFTH). DATA OBTAINED UNDER EXPERIMENTAL CONDITIONS INCLUDED--(1) REACTION TIME TO LIGHTS AND TONES, PRESENTED SEQUENTIALLY, (2) VIGILANCE PERFORMANCE UNDER CONDITIONS OF AUDITORY, VISUAL, AND COMBINED AUDITORY-VISUAL PRESENTATION, (3) AUDITORY AND VISUAL DISCRIMINATION SKILLS WITH MEANINGFUL AND NONMEANINGFUL MATERIAL, (4) AUDITORY AND VISUAL SPAN OF WORDS AND DIGITS, (5) AUDITORY AND VISUAL SERIAL LEARNING OF WORDS, AND (6) CONCEPT FORMATION SKILLS. RESULTS OF THIS STUDY INDICATED THAT READING MAY BE ADVERSELY AFFECTED BY ANY ONE OF THE PSYCHOLOGICAL PROCESSES OF DISCRIMINATION, MEMORY, LEARNING, AND CONCEPTION. IT WAS ALSO DETERMINED THAT DIFFICULTIES IN ATTENDING, MEMORIZING, OR LEARNING WITHIN PARTICULAR SENSORY MODES ARE RELATED TO READING RETARDATION. IT APPEARED THAT THE READING LEVELS OF YOUNGER CHILDREN WERE AFFECTED BY DIFFICULTIES IN DISCRIMINATION. (WB)