Students in Thailand did fieldwork to investigate the effects of urban sprawl taking place around their school. One group of students measured variations in water pollution in local lakes, and did an environmental quality survey in areas near the school. They concentrated their investigation on the following hypotheses: Hypothesis 1: Lakes are more polluted in areas where housing has been there longer. Hypothesis 2: The overall quality of the environment is better in the older housing area. The students selected three sites in different areas around their school to do their fieldwork. They are described in Table 8.1 below. Table 8.1 Site 1 | an area of older, more expensive housing on a secure estate Site 2 | an area of modern, cheaper housing alongside a main road Site 3 | an area where new housing was being completed