## 4 Results and Discussion
### Correlation Analysis  
Figure 9 below illustrates the correlations among passengers' ratings for various airport services or aspects. Three types of correlations were identified: (1) Strong positive correlations (values close to 1) suggest that as one aspect improves, another improves. For instance, the strong correlations between terminal seating, terminal signs, and food and beverages indicate that enhancements in one of these areas may be associated with improvements in the others; (2) Moderate correlations: These are observed between aspects such as airport shopping and WiFi connectivity, suggesting a moderate relationship; (3) Lower correlations (values closer to 0) indicate less direct relationships between these aspects. This implies that improvements in these areas could be managed independently without significant direct impacts on each other. These correlation insights can help airport management prioritize improvements accordingly.  
Then, the correlation coefficients between the 'Recommended' variable and the airport features were calculated, to determine the impact of various airport features on the likelihood of an airport being recommended by reviewers. These results indicate a positive correlation between all examined features and the likelihood of an airport being recommended. Terminal cleanliness exhibited the highest correlation (\(r\) = 0.517), suggesting it is the most influential factor among those analysed. Airport shopping (\(r\) = 0.451) and airport staff (\(r\) = 0.376) also showed relatively strong correlations, highlighting their importance in the overall airport experience. Terminal signs (\(r\) = 0.257), terminal seating (\(r\) = 0.314), food and beverages (\(r\) = 0.283), and WiFi connectivity (\(r\) = 0.212) demonstrated moderate correlations. This suggests that while these features are important, they may be less critical in influencing recommendations compared to cleanliness and shopping facilities.  
Furthermore, the comparison of average ratings across different aspects of airport services based on the sentiment of the passengers' review reveals some interesting patterns: (1) Terminal cleanliness: Positive sentiments correlate with higher ratings in cleanliness, with an average of 3.30 for positive sentiments versus 2.37 for negative sentiments; (2) Terminal seating: Positive sentiments lead to slightly higher seating ratings, 1.35 compared to 1.04 for negative sentiments; (3) Terminal signs: There is a noticeable difference in signage ratings, with 1.76 for positive sentiments against 1.49 for negative; (4) Food and beverages: Positive reviews also tend to rate food and beverages slightly better (1.24) than negative reviews (0.99); (5) Airport shopping: There is a significant difference in shopping ratings, 2.52 for positive sentiments compared to 1.70 for negative; (6) WiFi connectivity: WiFi ratings are marginally better in positive reviews (1.05) than in negative ones (0.92); (7) Airport  
Figure 8: The percentage of airport-related services rated by passengers.  
staff: Staff ratings also reflect a similar trend, with 1.37 for positive sentiments versus 0.93 for negative. These findings suggest that the sentiment expressed in the passengers' review words generally aligns with the numerical ratings given across various service categories. Positive textual feedback correlates with higher service ratings and negative feedback with lower ratings.