According to a recent encyclopedia entry about dog breeds, Labrador retrievers come in two specific breeds: English and American. The article cites six studies from several scientific journals about dog breeding showing that males of both breeds usually average 29-41 kg (65-90 lb) in weight, and females usually average 25-32 kg (55-70 lb) in weight. Anna’s female Labrador retriever weighs 38 kg (83 lb). What does Anna’s dog’s weight indicate about the reliability of this source?
This is still a reliable source because it clearly cites scientific research. Sometimes sources flatly contradict a given statement, study or an existing fact. In that case, there are things that we need to consider like the source of the evidence, is there outside evidence that supports one of the sources, and how do the conflicting sources fit with other existing facts present about the topic.
