The volume of newspaper help-wanted ads dipped.

But the overall labor picture remained improved over a year ago, the Conference Board reported. The business research group said its Help-Wanted Advertising Index dropped to 143 in May, one point below April but still 15 points higher than the year-ago reading of 128. The index uses a 1967 base of 100. The index, which is sensitive to labor demands and general business conditions, measures the volume of classified advertising in 51 major newspapers nationwide.