Of all the defects in formed concrete surfaces- honeycomb, grout leaks through forms, sand-streaking form heavy bleeding along the form, lift lines, variation in color an soft areas- the one that is most troublesome is surface voids. It is also the most difficult to control and the cause of the most controversy. Surface voids are called bugholes in the United States and blow holes in many other countries. The observer is struck by the wide difference in the number of bugholes form one job to the next, and even in different parts of the same placement where conditions appear to be identical. Research to come up with a yardstick for rating concrete surfaces with respect to bugholes can be divided into two categories: (1) counting and measuring the voids and (2) other methods. The Cement and Concrete Association and others in Great Britain and Sweden have tried to develop a yardstick for rating concrete surfaces. Early attempts involved counting and measuring the diameter of the individual voids within a selected area and expressing the area of voids as a percent of the selected area. However, there seems to be some trend away from this approach. The New Zealand Portland Cement Association has recently recommended dividing permissible blowholes into three categories without actually counting and measuring them: (1) none permitted, (2) permitted, and (3) minor occurrence permitted. These terms are not clearly defined, however, and the first category is probably beyond the present state of the art. Most researchers who have studied the problem believe the voids are entrapped air from incomplete consolidation of the concrete: others believe they are mostly water pockets. Water has actually been found when drilling into voids seen through transparent forms; however, these could originally have been air pockets into which water has bled after the placement was completed. The actual nature of the voids should be definitely established before proceeding with other research on the bughole problem.