Polluted objectivity?

D is frustrated; she’s working on a report and presentation of her last season’s data, due in 2 weeks, and her results aren’t turning out as she planned. In fact, they’re coming out quite the opposite of what she expected. Let’s back up a bit and explain how Delilah found herself in this situation. In tenth grade she was inspired by Rachael Carson’s book Silent Spring and decided to make a career of combating environmental destruction. In college she majored in environmental studies, and planned to work for an environmental lobbying group. She duly joined a master’s program at Northern State, thinking she would be more effective if she had a working knowledge of the science used to track humanity’s negative effect on the environment. For her research, she wanted to look at one specific human impact on the environment. She chose to study the effects of a paper mill’s effluent on the insect community in a local stream, the Upper Swift. Her main questions revolved around how much insect diversity decreased downstream of the discharge point, and how far away you had to look before diversity recovered. Her advisor, Frank, knew some people at the paper mill and helped Delilah get permission to work on the property. She could sample the effluent itself (which meets all regulatory requirements) and the catchment area before it merged with the stream. In return, she agreed to give the company a report on her results. This is the deadline that looms. Delilah sampled the stream every 20 m for 500 m upand downstream from the discharge point. She was dismayed to find that diversity was actually greater in the polluted region downstream than it was upstream. She was encouraged that diversity climbed the farther downstream she sampled, but this wasn’t statistically significant. Frank reminded her that the sampling devices she used were cheap and easy to use, but they tended to miss some groups of insects that a more sophisticated sampling protocol would get. Perhaps more things were missed upstream than down. He also asked whether the substrate differed. When Delilah checked, it turned out that rocky areas were notably more common downstream. Unfortunately, her sampling stations were not located in a way that easily let her compare diversity in specific substrate types.