Learning the properties of an image associated with human gaze placement is important both for understanding how biological systems explore the environment and for computer vision applications. There is a large literature on quantitative eye movement models that seeks to predict fixations from images (sometimes termed "saliency" prediction). A major problem known to the field is that existing model comparison metrics give inconsistent results, causing confusion. We argue that the primary reason for these inconsistencies is because different metrics and models use different definitions of what a "saliency map" entails. For example, some metrics expect a model to account for image-independent central fixation bias whereas others will penalize a model that does. Here we bring saliency evaluation into the domain of information by framing fixation prediction models probabilistically and calculating information gain. We jointly optimize the scale, the center bias, and spatial blurring of all models within this framework. Evaluating existing metrics on these rephrased models produces almost perfect agreement in model rankings across the metrics. Model performance is separated from center bias and spatial blurring, avoiding the confounding of these factors in model comparison. We additionally provide a method to show where and how models fail to capture information in the fixations on the pixel level. These methods are readily extended to spatiotemporal models of fixation scanpaths, and we provide a software package to facilitate their use.visual attention | eye movements | probabilistic modeling | likelihood | point processes H umans move their eyes about three times/s when exploring the environment, fixating areas of interest with the highresolution fovea. How do we determine where to fixate to learn about the scene in front of us? This question has been studied extensively from the perspective of "bottom-up" attentional guidance (1), often in a "free-viewing" task in which a human observer explores a static image for some seconds while his or her eye positions are recorded (Fig. 1A). Eye movement prediction is also applied in domains from advertising to efficient object recognition. In computer vision the problem of predicting fixations from images is often referred to as "saliency prediction," while to others "saliency" refers explicitly to some set of low-level image features (such as edges or contrast). In this paper we are concerned with predicting fixations from images, taking no position on whether the features that guide eye movements are "low" or "high" level.The field of eye movement prediction is quite mature: Beginning with the influential model of Itti et al. (1), there are now over 50 quantitative fixation prediction models, including around 10 models that seek to incorporate "top-down" effects (see refs. 2-4 for recent reviews and analyses of this extensive literature). Many of these models are designed to be biologically plausible whereas others aim purely at prediction (e.g., ref. 5). Progress is meas...