The problem with which this investigation is concerned is an analysis of errors in looping and assignment made by novice assembly language computer programmers. This analysis is made after subjects write three computer programs. The verbal definition of the problem for each program specifies, without naming, either a for, while, or repeat looping structure. The purposes of the study are the following; to determine whether using the appropriate looping structure is related to writing a correct program; to determine the incidence of assignment errors in incorrect programs; to determine the degree of relationship between mathematical aptitude, and the type of assignment errors made; to determine the degree of relationship between use of the appropriate looping structure and mathematical, verbal, and scholastic aptitude; to determine the degree of relationship between gender and use of the appropriate looping structure, and to determine the degree of relationship between gender and the number of assignment errors.