The traditional hypothesis that extreme attitudinal positions on controversial issues are likely to produce low understanding of messages on these issues--especially when the messages represent opposing views--is tested. Data for test of the hypothesis are from two field studies, each dealing with reader attitudes and decoding of one news article on each of two issues. One survey was in St. Paul and dealt with open housing and police enforcement of laws. The other was in Monticello, Minnesota area northwest of Minneapolis and was concerned with the DDT banning issue and a controversy over construction and operation of a nuclear generating plant. Each respondent in the two studies was asked to read and state from recall his understanding of two articles which had actually appeared in one of the Twin Cities metropolitan newspapers in months preceding the studies. Position on each issue was measured according to summated responses to seven agree-disagree items selected from statements attributed to various interest groups, public officials, and spokesmen. Understanding was defined operationally as the number of accurate statements offered by a respondent about an article after reading it. The most relevant data for the narrower selective understanding hypothesis are the eta coefficients for the association between attitudes and understanding. It was found that for DDT and the two St. Paul issues, there is no consistent relationship between position and understanding. Education and open-mindedness remain the principle correlates of understanding on these two issues. (CK)