# NFC Tag Awareness and Its Visual Implementation on Food Packaging: Case Study in Slovenia
## 2 Materials and Methods
Personal data were not collected, and all responses were anonymized to protect the participants' privacy. In the research conducted, no participants were excluded, and all available data were utilized. A well-known brand packaging (Alpsko) and a fictitious packaging design (Natalis) of UHT milk were used to assess the visibility of NFC tag placement. Eye-tracking technology was employed to obtain non-subjective measurements of the areas of the NFC tag that received quicker and longer observations. The eye-tracking system used was the Tobii X120, manufactured by Tobii Technology AB of Sweden, capable of detecting real-time eye movements at a sampling rate of 120 Hz. The packaging samples were displayed on a 52.04 \(\times\) 32.60 cm HP ZR24W screen (Hewlett-Packard Inc, Palo Alto, CA, USA) with a resolution of 1920 \(\times\) 1200 px and viewed from a distance of 60 (+/-1) cm. Eye movement tracking was recorded using the Tobii Studio 3.2.1 software. The measurements were performed in a quiet room with neutral matte gray walls. Prior to the measurement, each participant was allowed to adapt to the lightning conditions of the room for 5 min and underwent a 9-point screen-based calibration. All participants had normal or corrected-to-normal vision. Each participant viewed a total of 26 images of packaging designs, randomized for each participant to mitigate order effects. From 26 images of packaging designs, 16 were important for our study and were further evaluated. Each image was presented automatically on the screen to each participant for 5 s. A gray masking screen was inserted for 2 s between images to control for carryover and order effects. Participants were asked to look at the displayed image while their eye movements were recorded. When evaluating eye movements, the following measurements were taken into account:  
* Time to first fixation (TFF) of the area of interest (AOI), assessing how long it takes for the observer to fixate his gaze on the active area of interest from the start of the visual display. * Total fixation duration (TFD) with respect to an area of interest. * A heat map, which is a graphic that can effectively reveal the center of the visual attention by showing how gazes are dispersed over the stimuli. The data and results were statistically evaluated, and the following statistical methods were utilized: \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline  & & \multicolumn{6}{c}{**Segmentation of Group 1 and Group 2**} \\ \hline  & & & **Education Level (\%)** & & & **Generation (\%)** \\ \hline Groups & & & & & & & & \\ (information retrieved) & N/Avg. age & Below level 5 & Level 6/1 & Level 6/2 and above & BB & X & Y & Z \\ \hline GROUP 1 & & & & & & & & \\ Online survey respondents & 164/32.1 & & & & & & & \\ (knowledge, design implementation) & & & & & & & & \\ \hline GROUP 2 & & 17.7 & 56.1 & 26.3 & 5.1 & 21.2 & 37.4 & 36.4 \\ Interviewees & & 34/21.1 & & & & & & & \\ (knowledge, eye-tracking) & & & & & & & & \\ \hline G1 + G2 & 198/26.6 & & & & & & & \\ \hline \multicolumn{8}{c}{**Segmentation of Group 3**} \\ \hline GROUP 3 & & & & & & & & & \\ Focus group participants & 50/22.5 & 100 & & & & & \\ (usage, design implementation) & & & & & & & \\ \hline \hline \end{tabular} N = number of participants, Avg. age = average age, BB = baby boomers.  
\end{table} 
Table 1: Distribution by age and education for all participants. Chi-square test  
Purpose: to analyze the associations between categorical variables, that is, recognition and knowledge of NFC tags based on factors like education level and generation. Reason for use: chi-square tests were used to compare the observed frequencies (recognized vs. not recognized, known vs. not known) with the expected frequencies to determine if there were significant associations between variables and to examine if there were significant relationships among factors like education level, generation, and recognition/knowledge of NFC tags.