Passage Summary: Anthropologists think living with the people they study is a great way to learn, but they actually value it too much because they don't realize how much their presence messes up the very thing they are trying to see.

Conclusion: Anthropologists generally place too much value on the effectiveness of field studies.

Reasoning: While researchers acknowledge their presence has an impact on the community, they fail to realize the true magnitude of how much they alter the group they are observing.

Analysis: To find the conclusion here, look for the author's main takeaway or opinion rather than just background facts. The first sentence sets the stage, while the second sentence delivers the 'punchline' or the author's primary claim. The final sentence serves as a supporting premise, explaining why the author believes the usefulness is overrated. It’s a classic case of an expert being a bit too close to their own work to see the flaws.