Our design highlights three major characteristics of diffusion processes in social media:
- the temporal trend, （时间趋势）
- social-spatial extent, （空间演变）
- and community response of a topic of interest.（社会反映）
Whisper, aimed at answering：
- when,
- where,
- and how an idea is dispersed.
Our design incorporates several novel visual ingredients:
- a hierarchical social-spatial layout,（分层布局）
- the pathways of information flow, （传播路径）
- and a dynamic diffusion series（动态传播序列）
We visualize such social, spatiotemporal processes based on the metaphor of a “sunflower” whose seeds are often dispersed far away.
In Whisper, original tweets are placed inside a circle in the center.
A pathway is created to connect a tweet to a user community once it gets retweeted by that community.
A sequence of color-coded retweet glyphs moving along the pathways indicates the timing and sentiments of the retweets
Visualization design:
Design Goals:
1.design rationales
A. Visual narrative structure.
The metaphorical pattern of a sunflower makes it easy for users to grasp the visual narrative of the information diffusion and enables an immediate comparison without spending much effort learning the meaning of each component.
（向日葵模式使信息传播更易理解）
B. Role identification.
tweets are visually classified into two categories:
thetweets from media broadcasters and opinion leaders
and the tweets from other users.
C. Diffusion process unfolding
a multi-step model [32] which states that an information flow
first transits from mass to opinion leaders who,
in the second step, significantly accelerate the spreading of the information.
Through social media, the spreading of information can be accelerated in a very short period of time [34], and the propagation may travel in arbitrary directions
in the social network simultaneously.
D. Monitoring and scrutinizing.
Whisper seeks to support two modes of visualization:
(1) the dynamic view shows the tweets and retweets generated in real time, which helps capture what is happening about the topic of interest;（实时信息）
(2) the static view with timeline control enables users to explore the historical data and to support in-depth visual analysis [40].（历史信息）
E. Visual clutter reduction.
We use a flux line-drawing algorithm to create diffusion pathways that reduce crossings.
2.visual mataphors and encodings
Topic disc:
the dots packed in the center represent inactive tweets that have never been retweeted
and the dots surrounding the topic disc are the active tweets that have been retweeted within a given period of time.（通过转发行为由内向外移动）
we sort inactive posts in an increasing order based on their influences
The active tweets：
The outmost rings contain the latest tweets, whereas those inner rings contain relatively older tweets in a temporal
order.
User group:
基于地理信息将用户分组。
Diffusion pathway:
Visual encoding:
Color hue is used to encode sentiments.
Opacity is used to encode activeness.
Size is used to encode expected influence.
Shape is used to encode user types.
3.interactions
各种交互操作
