Data from the U.S. Department of Education Office for Civil Rights showing that Indiana ranked first in the nation in expulsion and ninth in the nation in expulsions in the most recent available statistics cannot help but raise questions concerning why this is so. At a preliminary presentation of that data before the Indiana State Legislature in the Spring, 2004 session, some respondents suggested that Indiana's relatively high rate of expulsion may be a function of how expulsion is defined. The argument was made that, since Indiana defines an expulsion as any school removal over 10 days, by definition the state would count more school removals as expulsions than other states that may define a higher number of days (e.g., 15 or 20 days) as the dividing line between what is counted as a suspension or an expulsion. Thus Indiana's apparently high rate of expulsion, the argument continued, was simply a function of how the state counts expulsions relative to other states. This is indeed one of many possible hypotheses concerning factors in state statute that might be associated with higher rates of school expulsion. One might, for example, argue that other characteristics of state definition--the presence of zero tolerance policies (not present in Indiana's definition), or relatively broader definitions of infractions subject to expulsion (which Indiana does have)--might be the most important factors in determining a state's rate of expulsion. Only an empirical study of the relationship of such characteristics and state rates of expulsion could adequately test such hypotheses. In order a range of possible reasons for Indiana's rate of expulsion, the authors examined and coded state definitions of expulsion in all 50 states. To find all statutory language related to out-of-school suspension or school expulsion, the authors examined the Education statutes or codes for all 50 states. They examined all statutes or codes related to out-of-school suspension and expulsion for each state and were able to comprise five primary categories: definition/length, types of infractions, alternatives to suspension or expulsion, due process, and corporal punishment. Differences among states in these characteristics were then examined with respect to state rates of out-of-school suspension or expulsion in an attempt to determine which if any of those characteristics predict higher rates of school exclusion. (Contains 5 tables.) [This document was produced by the Center for Evaluation & Education Policy.]