Quantitative Reasoning About Duggan's Article
The researchers do not also describe sampling method they adopted in the study. According to Lohr (2009), success of a research in achieving study objectives depend on research design adopted. Findings of Duggan et al are, therefore, questionable. In other words, the study possibly had certain prejudices. Research biases, also known as systematic errors, distort reproducibility of a study. In particular, the study of Duggan et al was associated with selection biases and measurement biases.