Table 4 Comparison of existing methods and our proposed approach.

From: Graph-enhanced implicit aspect-level sentiment analysis based on multi-prompt fusion

Method name

Core mechanism/improvement

Advantages

Limitations

Extraction Models (DP-ACOS/Extract-Classify-ACOS/SGTS)

Multi-stage extraction

Intuitive method, stable training, effective for explicit information extraction

Multi-step structure prone to error propagation, relies on explicit annotations, difficult to handle implicit content

Seq2Path

Path sequence generation

Suitable for explicit information, clear structure

High miss rate when path clues are absent, difficult to handle implicit quadruples

BART-CRN

Revisiting mechanism

Can correct some initial wrong predictions

Implicit quadruples lack annotation, revisiting mechanism struggles to perceive them

ILO + UAUL

Hard sample optimization + Unlikelihood learning

Reduces repeated errors, focuses on complex instances

Contextual dependencies not modeled, effectiveness limited to within-sentence context

DLO + UAUL

Positive/Negative likelihood joint optimization + Unlikelihood learning

Better distinguishes correct/incorrect predictions, handles complex sentences well

Still limited in capturing long-distance dependencies

Special_Symbols

Special symbols to mark aspect/opinion/sentiment + Unlikelihood learning

Explicit markers help the model recognize implicit clues

Symbols are insufficient to express deeper meanings in complex contexts

Paraphrase

Text paraphrasing to assist implicit reasoning

Enhances semantic diversity, improves adaptability to varied expressions

Easily introduces noise, may misassociate unmentioned content

Proposed Method

Multi-order prompt fusion + Graph Neural Network + Pointer-index generation mechanism +

Strong implicit reasoning, accurate long-distance dependency capture, complete structural information

Requires high reasoning ability, slightly higher training complexity