A fundamental understanding of what is happening to American courts depends in large part on knowledge of patterns of judges' time use. Overall, studies tend to show that judges spend about 4 hours daily on the bench, although the variation is considerable from judge to judge and system to system. Factors contributing to such differences are judicial attitudes toward what is desired and emphasized by the system, court size, type of court (appellate judges have less bench time than lower court judges), and type of case (criminal cases generally involve more bench time than civil cases). Differences in judges' use of time also depend to a great extent on the degree of specialization among personnel in court systems. In many courts, for example, various administrative functions may be handled by court officers acting in the name of judges. Evaluations of the quality of judicial performance are still in their infancy, with most of such evaluations consisting of semi-official or unofficial polls of the bar. An obvious discrepancy between determinations of the use of judge-time and measures of the quality of judicial performance exists. Measures of judicial performance tend to focus on courtroom performance. This fails to give attention to the 25 to 50 percent of time judges devote to non-bench duties. Evaluations of judicial performance should give more attention to the full range of duties performed by judges. Thirty-eight references are listed, and data from various studies cited in the study are provided.