The subjectivity and non-probability based nature of unit selection (., selecting people, cases/organisations, etc.) in purposive sampling means that it can be difficult to defend the representativeness of the sample. In other words, it can be difficult to convince the reader that the judgement you used to select units to study was appropriate. For this reason, it can also be difficult to convince the reader that research using purposive sampling achieved theoretical/analytic/logical generalisation . After all, if different units had been selected, would the results and any generalisations have been the same?
In the Philippines, an academic thesis is named by the degree, such as bachelor/undergraduate thesis or masteral thesis. However, in Philippine English , the term doctorate is typically replaced with doctoral (as in the case of "doctoral dissertation"), though in official documentation the former is still used. The terms thesis and dissertation are commonly used interchangeably in everyday language yet it generally understood that a thesis refers to bachelor/undergraduate and master academic work while a dissertation is named for doctorate work.