Determination of fluid category 2. Water in fluid category 1 whose aesthetic quality is impaired owing to: 1  a change in its temperature; or. 2  the presence of substances or organisms causing a change in its taste, odour or appearance, including water in a hot water distribution system.
Credibility is defined as the quality or power of inspiring belief. Credible sources, therefore, must be reliable sources that provide information that one can believe to be true. It is important to use credible sources in an academic research paper because your audience will expect you to have backed up your assertions with credible evidence.
Erickson (1986) refers to quantitative research as process/product research where the role of the researcher, for example, is to look at causal links between teacher effectiveness, as measured on end of the year tests, and particular teaching practices.