Scatter plots are popular for displaying 2D data, but in practice, many data sets have more than two dimensions. For the analysis of such multivariate data, it is often necessary to switch between scatter plots of different dimension pairs, e.g., in a scatter plot matrix (SPLOM). Alternative approaches include a "grand tour" for an overview of the entire data set or creating artificial axes from dimensionality reduction (DR). A cross-cutting concern in all techniques is the ability of viewers to find correspondence between data points in different views. Previous work proposed animations to preserve the mental map between view changes and to trace points as well as clusters between scatter plots of the same underlying data set. In this paper, we evaluate a variety of spline- and rotation-based view transitions in a crowdsourced user study focusing on ecological validity. Using the study results, we assess each animation's suitability for tracing points and clusters across view changes. We evaluate whether the order of horizontal and vertical rotation is relevant for task accuracy. The results show that rotations with an orthographic camera or staged expansion of a depth axis significantly outperform all other animation techniques for the traceability of individual points. Further, we provide a ranking of the animated transition techniques for traceability of individual points. However, we could not find any significant differences for the traceability of clusters. Furthermore, we identified differences by animation direction that could guide further studies to determine potential confounds for these differences. We publish the study data for reuse and provide the animation framework as a D3.js plug-in.

翻译：散点图广泛用于二维数据的可视化，但实际数据往往包含超过两个维度。在分析此类多元数据时，通常需要在不同维度对的散点图之间切换（例如散点图矩阵中的操作）。另一种方法是对整个数据集进行"全局巡视"，或通过降维创建人工轴。所有技术中的关键共性问题在于观察者能否在不同视图间建立数据点的对应关系。已有研究提出通过动画保持视图切换时的心理地图，并追踪同一数据集散点图中的数据点和聚类。本文通过众包用户研究，聚焦生态效度，评估了多种基于样条和旋转的视图过渡技术。基于研究结果，我们评估了每种动画在视图变换中追踪点和聚类的适用性，并探究水平/垂直旋转顺序对任务准确性的影响。结果表明，采用正交相机投影或深度轴分阶段展开的旋转方法在单个点可追踪性上显著优于其他动画技术。我们进一步提供了用于追踪单个点的过渡动画技术排名，但未发现聚类可追踪性存在显著差异。此外，我们识别出不同动画方向导致的差异，这可为后续研究确定这些差异的潜在混淆因素提供指导。我们已将研究数据开源供复用，并以D3.js插件形式发布动画框架。