New media technology is altering many aspects of mass communication processes. One of the most profound changes, especially in the newspaper industry, lies in the rise of speed-driven journalism, with growing emphasis on what is new or happening now. With more newspapers adopting this speed-driven news practice, the nature of its impact on journalists and audiences necessitates empirical examination, and this dissertation seeks to contribute to the professional and academic literature from a two-part, mixed method approach. Through interviews with journalists, study 1 sought to understand journalists' view of how speed-driven journalism affects their professional norms, routines and output, and how social media factors into the speed-driven online media landscape. The interviewees were also asked to discuss their view on how speed-driven journalism affects news audiences in terms of news credibility, news use, and paying intent. Based on findings from study 1, an experiment on news audiences was conducted in study 2 to assess the impact of speed-driven journalism on news credibility, future use, paying intent, readability and selective scanning. Key findings from both studies include: (1) Whereas most interviewees in study 1 believed that speed harms news credibility but boosts news use, the experiment in study 2 revealed that speed neither harms news credibility nor promotes future use. (2) Speed-driven journalism has no effect on selective scanning or audiences' paying intent. (3) In terms of readability, news stories presented in the live blog-like format are deemed harder to follow when compared to those presented in the traditional format. This dissertation advances the hierarchy of influence model by uncovering the effect of perceptual disconnect on speed-driven news practices at the social institutions level. That is, journalists are wrong at times in their assessment of how audiences engage with and are affected by new media technology, but nonetheless proceed to produce news and content based upon their mistaken judgment. / text