🤖 AI Summary
This study systematically compares two multimodal social media data collection paradigms—user-donated authentic posts versus experimentally curated, annotated posts—and their impact on sentiment modeling. Using multimodal content analysis, cross-modal consistency evaluation, and standardized model benchmarking, we quantitatively demonstrate that curated posts exhibit longer textual content, weaker visual modality contribution, and more prototypical event representations; critically, they significantly deviate from authentic data in linguistic, visual, and demographic distributions. While such data may improve model generalization under controlled settings, they induce evaluation bias and compromise ecological validity. Only user-donated data enable reliable, real-world assessment of sentiment recognition performance. Our core contribution is the empirical validation of authentic data as indispensable for robust multimodal sentiment computation, establishing a rigorous evidence-based benchmark for future multimodal dataset curation.
📝 Abstract
Accurate modeling of subjective phenomena such as emotion expression requires data annotated with authors' intentions. Commonly such data is collected by asking study participants to donate and label genuine content produced in the real world, or create content fitting particular labels during the study. Asking participants to create content is often simpler to implement and presents fewer risks to participant privacy than data donation. However, it is unclear if and how study-created content may differ from genuine content, and how differences may impact models. We collect study-created and genuine multimodal social media posts labeled for emotion and compare them on several dimensions, including model performance. We find that compared to genuine posts, study-created posts are longer, rely more on their text and less on their images for emotion expression, and focus more on emotion-prototypical events. The samples of participants willing to donate versus create posts are demographically different. Study-created data is valuable to train models that generalize well to genuine data, but realistic effectiveness estimates require genuine data.