Shortening Psychological Scales: Semantic Similarity Matters

In this study, we proposed a novel scale abbreviation method based on sentence embeddings and compared it to two established automatic scale abbreviation techniques. Scale abbreviation methods typically rely on administering the full scale to a large representative sample, which is often impractical in certain settings. Our approach leverages the semantic similarity among the items to select abbreviated versions of scales without requiring response data, offering a practical alternative for scale development. We found that the sentence embedding method performs comparably to the data-driven scale abbreviation approaches in terms of model fit, measurement accuracy, and ability estimates. In addition, our results reveal a moderate negative correlation between item discrimination parameters and semantic similarity indices, suggesting that semantically unique items may result in a higher discrimination power. This supports the notion that semantic features can be predictive of psychometric properties. However, this relationship was not observed for reverse-scored items, which may require further investigation. Overall, our findings suggest that the sentence embedding approach offers a promising solution for scale abbreviation, particularly in situations where large sample sizes are unavailable, and may eventually serve as an alternative to traditional data-driven methods.