# Visual Performance Assessment of Videos--A Case Study of the Game \"Spot the Difference\"
## 3 Results and Discussion
### Accuracy  
The ANOVA results for accuracy indicated that background (F = 11.599, \(p<0.05\)), video type (F = 10.101, \(p<0.05\)); the interaction between video type and arrangement (F = 11.300, \(p<0.05\)); and the three-way interaction among background, video type, and arrangement (F = 63.325, \(p<0.01\)) were the significant factors. As shown in Figure 3, the performance of accuracy without a background was better in the top-to-bottom animation and the left-to-right text, while the accuracy with a background was superior in the left-to-right animation and the top-to-bottom text. In addition, text with a background in the left-to-right arrangement showed the lowest accuracy. [PERSON] et al. [8] found that a complex background produced an inferior performance in visual searching. [PERSON] [24] also showed that the horizontal arrangement of phonetic symbols brought about an inferior performance in sending Chinese text messages. A possible reason for this outcome may be that the average scanning distance from left to right is longer than that from top to bottom in a video, especially one with a background, resulting in a low accuracy. In order to see the characters in text clearly, a top-to-bottom arrangement generated a short scanning distance and resulted in a high accuracy. For the interaction between video type and arrangement, as shown in Figure 4, the animation with a left-to-right arrangement and text with a top-to-bottom arrangement had a better accuracy. It can be inferred that a left-to-right arrangement is suitable for animations while a top-to-bottom arrangement is appropriate for texts. Participants may be used to scanning objects on screens from the left to the right in their daily lives, resulting in a high accuracy for left-to-right animation. As previously mentioned, a short scanning distance was found for top-to-bottom text and also resulted in high accuracy. Finally, similar to the results in the three-way interaction, the left-to-right text in Figure 2 showed the lowest accuracy.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Source of Variance** & **Accuracy** & **Number of Fixations** & **Subjective Visual** \\  & & & **Fatigue** \\ \hline Background (B) & 11.599 * & 4.160 * & 7.664 * \\ Film type (F) & 10.101 * & 4.391 * & 5.827 * \\ Arrangement (A) & 2.145 & 6.823 * & 0.611 \\ B \(\times\) F & 0.059 & 0.328 & 0.539 \\ B \(\times\) A & 0.431 & 5.832 * & 0.026 \\ F \(\times\) A & 11.300 * & 3.462 & 5.486 * \\ B \(\times\) F \(\times\) A & 63.325 ** & 1.535 & 2.803 \\ \hline \hline \end{tabular}  
* \(p<0.05\); ** \(p<0.01\).  
\end{table}
Table 1: ANOVA results for dependent variables.  
Figure 3: The interaction among background, film type, and arrangement for accuracy.  
The results also indicated that the background was a significant factor. The accuracy of the video without a background (M = 0.604) was significantly lower than that in the video with a background (M = 0.518). [PERSON] and [PERSON] [9] indicated that the difficulty of a visual search affected efficiency. [PERSON] et al. [10] also found that high visual complexity and high verbal ambiguity resulted in a low accuracy and slow response time on visual search tasks. In this study, the white color was set for the without background context and scenery was set for the with background context. Compared to the monochromatic color, scenery with multiple colors could produce more visual stimuli and result in a low accuracy.  
The results further indicated that video type was significant, with the accuracy of the text (M = 0.520) being significantly lower than that of the animation (M = 0.602). As participants have to spend more time in watching and understanding the meaning of texts, it makes sense that the accuracy of texts is lower than that of animation. The results from the interaction between video type and arrangement also showed that watching animation (M = 0.676) produced a higher accuracy than watching text (M = 0.488) in the left-to-right arrangement.