A two-phase investigation of characteristics associated with student achievement in elementary and secondary reading centers in the Houston (Texas) Independent School District is described and evaluated in this paper. After presenting background information about the centers, the paper describes the first phase of the investigation, which revealed a significant correlation between consultants' ratings of reading center characteristics and measures of student achievement, and explains the expanded rating procedures used in the second phase of the investigation. It then presents results of correlations of the two process evaluation procedures, a factor analysis of the rating scales used, and a regression analysis performed with data from the elementary reading centers. The paper concludes that the reading center process evaluation procedures constituted a rather weak predictor of student achievement, that the observation form showed promise but needed to be evaluated with a larger sample of centers, and that certain methodological problems needed to be overcome. Tables of data are included; appendixes present the procedural rating form used in the first phase of the investigation, a completed procedural rating form of the kind used in the second phase, and a reading center observation form. (GT)