This study used data from the homicides in Chicago 1965-1995 dataset (N=9,340) to examine the relationship between the use of certain types of weapons in criminal homicides by gender, race, age, victim-offender relationship, motive, location, and changes over time. Differential association and sex-role theory were utilized to argue why gender differences would occur in type of weapon used in a homicide. Subculture of violence theory was used to emphasize that the place where the homicide occurs, the relationship between the victim and offender, motive of the offender, and the remaining variables affects the type of weapon used to kill. Significant relationships were found for all bivariate analyses performed. The type of weapon used to kill differs most by sex of offender, resulting in a moderately strong association. The type of weapon used to kill differs least by age of offender and although statistically significant, the association between the two is very weak.

A variable that may be associated with performance improvements is goal setting (within and across days). Easy-to-achieve goals will likely produce gradual trends in improvement and difficult-to-achieve goals steeper trends. The purpose of the current experiments was to study the effects of setting easy-to-achieve and difficult-to-achieve goals on the level, trend, and variability of correct, incorrect, and skip responses for math tasks when reinforcement contingencies and numbers of practices were held constant. Five undergraduate students answered math problems on flash cards in 30s timings. Single case design elements were used to evaluate the effects of different types of goals on the speed and accuracy of performance. The results revealed that goal setting primarily increased the frequency of incorrect responses and both the level and trend of skip responses. The implications of these findings and other important variables that influence the effectiveness of goal setting are discussed. In addition, the authors suggest guidelines to follow when implementing goals to improve performance.