## 2 Problem Statement
### Hypotheses  
Building upon the defined research objectives, this chapter introduces a set of hypotheses that served as framework that guided a systematic design of the ads in our study, testing their attention-grabbing properties.  
The foundation of our work lies in the acknowledgment that design quality is an important aspect of visual advertising that influences visual perception. Past research provides strong evidence for this. In a study on health advertisements [28], the authors selected the ads that varied in three levels of design quality (i.e., low, mid, high) and examined whether they gain different levels of participants' attention. They found that advertisements of low levels of design quality were viewed for a shorter amount of time than those of higher levels of design quality. A study on print versions of ads [29] showed that highly rated advertisements attracted more attention compared to those that were poorly rated. Judging the quality of design often involves considering the attractiveness of its elements. In a study on content elements of online banner ads, it was found that the image was the most attractive element [30]. The positive effect of images is supported by results of past research that examined the ability of visual ads to capture visual attention [31; 32]. The superiority of pictorial content was also demonstrated in a study in the field of health-related advertising. [PERSON] et al. [33] used eye-tracking technology to measure the attention toward text-only, image-only, and image-text ads promoting osteoporosis prevention. They found that the combination of text and images was more effective at attracting the participants' visual attention than the image-only and text-only ad formats. Past research suggests that graphic images included in cigarette warning labels on advertising improved recall of the warning and associated health risks [34]. They did so by attracting and maintaining the visual attention of smokers. Images used as an addition to text warnings on cigarette packaging may be particularly effective for youth populations, as suggested by [PERSON] et al. [35].  
Therefore, we set three hypotheses as follows. The first hypothesis refers to the effect of images (particularly illustrations) on the ad's ability to attract youth visual attention, while the second hypothesis refers to attention maintenance. Finally, the third hypothesis refers to the effect of illustrations on the ad's general noticeability. All the hypotheses focus on the visual attention variables because the attention is necessary for further processing [36] and greater visual attention may increase the possibility that young people will comprehend and remember the viewed information more easily.  
**H1:**: _A digital ad with text and an illustration attracts the attention of young viewers faster than a digital ad with no illustration._
**H2:**: _A digital ad with text and an illustration maintains the attention of young viewers for longer than a digital ad with no illustration._
**H3:**: _Young participants notice a digital ad with text and an illustration more than a digital ad with no illustration._  
To test the hypotheses, we employed an eye-tracking experiment. Eye tracking is considered as a suitable tool for consumer neuroscience research [37]. It allows a researcher to obtain quantitative data by recording viewers' eye movements during advertising exposition, and provides an insight into the viewers' underlying cognitive processes [35]. Hence, understanding eye movement behavior can be particularly useful in improving the persuasive quality of digital ads in public health promotion [27], especially of those that target young generations and gain their attention in today's media-saturated environment.