  The study of temporal trends in altmetrics is under-developed, and this
multi-year observation study addresses some of the deficits in our
understanding of altmetric behaviour over time. The attention surrounding
research outputs, as partially captured by altmetrics, or alternative metrics,
constitutes many varied forms of data. Over the years 2008-2013, a set of 7739
papers were sampled on six occasions. Five altmetric data sources were recorded
(Twitter, Mendeley, News, Blogs and Policy) and analysed for temporal trends,
with particular attention being paid to their Open Access status and
discipline. Twitter attention both starts and ends quickly. Mendeley readers
accumulate quickly, and continue to grow over the following years. News and
blog attention is quick to start, although news attention persists over a
longer timeframe. Citations in policy documents are slow to start, and are
observed to be growing over a decade after publication. Over time, growth in
Twitter activity is confirmed, alongside an apparent decline in blogging
attention. Mendeley usage is observed to grow, but shows signs of recent
decline. Policy attention is identified as the slowest form of impact studied
by altmetrics, and one that strongly favours the Humanities and Social
Sciences. The Open Access Altmetrics Advantage is seen to emerge and evolve
over time, with each attention source showing different trends. The existence
of late-emergent attention in all attention sources is confirmed.
