Accuracy and balance are fundamental principles of journalism worldwide. The main way that journalists ensure accuracy is by verifying the information in their stories against an independent account. Most journalists who report science must rely on scientific experts to verify the validity of claims they report. However, previous studies have found that science stories commonly contain only one source. Journalists typically maintain balance by fairly presenting opposing views. Previous studies show that when journalists present conflicting claims, they tend to balance the different opinions equally, regardless of the empirical evidence on which those claims are based. This thesis investigated verification and balance in New Zealand mass media science news, using a national survey and in-depth interviews with New Zealand journalists, and a content analysis of newspaper, radio and television coverage. The content analysis showed that verification was uncommon in New Zealand science news, and only 32% of science claim stories cited more than one source. Furthermore, 23% of stories were five sentences or shorter, and the majority of stories (65%) were drawn from overseas news organisations and wire services. When opposing views were presented, journalists tended to use a balancing strategy without any interpretation of which view was supported by the weight of evidence. The interviews indicated that these practices are partly influenced by time constraints. New Zealand almost completely lacks specialised science reporters, and only five of the surveyed journalists had a dedicated science round. Most surveyed journalists spent less than 20 hours per month reporting science, and few had formal training in science. However, journalists also said that the normative dimensions of being a journalist were important. In particular, journalists tended to value balance and fairness over ensuring the validity of claims they report. Exploratory focus groups suggested that audiences may also strongly value a balanced and unbiased approach to science reporting.