# Visual Performance Assessment of Videos--A Case Study of the Game \"Spot the Difference\"
###### Abstract
that the difficulty of the visual search test affects the search efficiency. According to [PERSON] et al. (2010), the background complexity and the clear or fuzzy description of the target affect the search speed and accuracy. It is concluded that the higher the complexity and description ambiguity are, the slower and harder it is to find the target. The current research uses videos to present the game \"Spot the Difference\", yet it is difficult to divide the videos into simple and complex groups based on the background colors during the design process. In this study, to test the absence of a background, the background picture is presented in a monochromatic system; meanwhile, when there is a background, the background picture is presented in a multi-color system. The videos are divided into two types: videos without a background (one color) and videos with a background (multiple colors). In addition, when people watch videos, different types of videos may have different impacts. Text represents the information in a verbal code, such as prose, expository text, or verbal instruction in written or spoken formats ([PERSON] and [PERSON], 2018). [PERSON] and [PERSON] (2018) investigated three kinds of reading contents: science-, literary-, and magazine-related. In contrast, pictures are defined as being associated with the represented object by similarity or common structural properties. When testing performance, [PERSON] and [PERSON] (2018) found that readers paid more attention to texts than pictures, and few fixations fell on pictures for English as a foreign language (EFL) beginners. [PERSON] and [PERSON] (2018) concluded that pictures increased readers' interest. [PERSON] (2018) indicated that pictures improve readers' processing of difficult text. However, [PERSON] and [PERSON] (2018) found that pictures may cause the seductive details effect, and they showed how pictures can easily affect people's reading performance. For videos, [PERSON] et al. (2018) indicated that visual analogy videos helped students improve their learning. [PERSON] et al. (2018) showed that the interaction with videos for students improves the quality and outcomes of online courses. [PERSON] et al. (2019) concluded that videos include text, audio, and visual features, resulting in a better performance in sentiment analysis. Based on these comparisons of texts and pictures, this study uses videos as the reading medium, and investigated two video types: text and animation. Layout style can also affect a subject's search direction. According to the literature, people subjectively prefer to choose the editing method in which an image is placed on the left side of the text ([PERSON] et al., 2018). In addition, significant differences in eyeball movements and attention shifts occur when viewing images versus reading text. When reading text messages, the eyeball moves up and down or left and right along the line of text, with alternate saccades and fixations. The saccade amplitude and average time of fixation for reading text is smaller and shorter than when viewing images, and the eye movement for reading text follows a left-to-right and top-to-bottom pattern. No such pattern occurs when viewing images ([PERSON] et al., 2018). Previous similar studies have investigated the difference between vertical and horizontal arrangements of text on PDAs and computer screens ([PERSON] and [PERSON], 2018; [PERSON], 2018), concluding that performance when reading vertical text is not always inferior to that when reading a horizontal format. [PERSON] (2018) investigated two types of phonetic symbols, including both vertical and horizontal arrangements, and found that the use of a vertical arrangement saves more time when sending Chinese text messages. Based on these factors, we aim to examine the differences between vertical and horizontal arrangements in this study. In summary, background, video type, and arrangement are three critical factors affecting people when watching \"Spot the Difference\" videos.