(FORTUNE Magazine) – We recently had a long, argumentative, and ultimately fruitless chat about GATB (pronounced gat-be) with Roberts T. Jones, assistant secretary of labor for employment and training. As Keeping Up readers well know, the General Aptitude Test Battery is controversial. Developed by the U.S. Employment Service, it is used by state employment agencies to decide which applicants get referred for job openings. There are disagreements about the precise correlations between test scores and job performance, but no dispute about the fact that the correlations are positive. The controversy centers on the fact that minority-group members have lower average GATB scores than do whites. Fearing that this could lead to a ban on the test, USES opted several years ago for ''within-group norming.'' This was a deal under which test takers got percentile scores reflecting only their rankings against other members of their own race. The Reagan Justice Department quite reasonably complained that the deal was discriminatory (i.e., against whites), and it made the test somewhat less useful as a predictor of job performance, but at least it enabled GATB to survive. Until now, that is. Precipitating our fruitless dialogue was the sudden announcement that GATB was to be withdrawn and, pending restudy, no longer used for job referrals. Jones kept saying that the test, being imperfect, could have ''the wrong kind of impact on some people''; and we kept saying that all imaginable alternatives were also imperfect. We conclude that the Labor Department just does not like tests that show group differences, period. Even if the National Research Council says the test provides ''useful screening information'' and predicts as well for blacks as for whites. And even though it has been a significant source of hires for FORTUNE 500 companies. We got through the dialogue without mentioning U.S. competitiveness, but just barely.