I was poking around the geoblogosphere, and I came across this post on field trip etiquette. One of Jessica's pieces of advice is to make sure your observations and interpretations are separate.
When I was an undergrad, I didn't have the years of experience to really see an outcrop and know what was going on. I would copy down whatever the professor said and then sort of took it on faith that there was a correct interpretation. But when I started doing fieldwork as part of my job, there was no correct interpretation waiting. There were no grades. All I had were my observations.
I started out by taking meticulous field notes because I didn't know which observations were important. I still take the most thorough field notes of any geologist I know, because I've learned from long experience that what observations are important may only be determined months later when I'm writing the report. And honestly, reviewers and regulators may have different interpretations of the data. But we can't have a good argument over interpretations if we don't have the basic observations first. What is the texture like? The color? Does it smell funny? Is there a sort of oily sheen on the soil samples? Are there any super-fine layers that could signal a change in geochemistry?
When I was a grad student, I taught a lab for a foundation undergrad geology course. I had the hardest time getting the students to focus on what they could see, rather than what they thought I wanted to hear. I knew what the formation was right away, but that was because my eyes had been trained by years of doing my own observations. What I wanted to see from students was a list of observations. Once they had those, they could crack open the book and try and figure out what they were looking at.
Without data, without notes, without a trail of evidence, your interpretation is just technical-sounding BS.