The Development of Vocational Agriculture before the Vocational Education Act 1963

Agricultural education programs are experiencing pressure to change from a variety of educational and societal influences. This pressure is not new to agricultural education programs. The evolution of vocational agriculture from 1945 to 1963 provides a historical example of vocational education change as a result of social influences. Rural America experienced unprecedented emigration after World War II. The loss of students from farming families, the intended recipients of vocational agriculture, should have hampered local programs, but in fact the opposite occurred: enrollment in vocational agriculture continued to grow. We examine how vocational agriculture teachers transformed local programs to match their emerging clientele before the Vocational Education Act of 1963

Vulnerability, Risk, and the Transition to Adulthood

Examines whether poverty and single parenthood influence the likelihood of risk behavior and dropping out among youth and how these behaviors affect the trajectory of connectedness and employment patterns in adulthood. Considers policy implications

Methods of sample size calculation for clinical trials

Sample size calculations should be an important part of the design of a trial, but are researchers choosing sensible trial sizes? This thesis looks at ways of determining appropriate sample sizes for Normal, binary and ordinal data. The inadequacies of existing sample size and power calculation software and methods are considered, and new software is offered that will be of more use to researchers planning randomised clinical trials. The software includes the capacity to assess the power and required sample size for incomplete block crossover trial designs for Normal data. Following on from these the difference between calculated power for published trials and the actual results are investigated. As a result, the appropriateness of the standard equations to determine a sample size is questioned- in particular the effect of using a variance estimate based on a sample variance from a pilot study is considered. Taking into account the distribution of this statistic alternative approaches beyond power are considered that take into account the uncertainty in sample variance. Software is also presented that will allow these new types of sample size and Expected Power calculations to be carried out