Organizational research increasingly uses natural language processing (NLP) to measure textual similarity. Despite common usage, the meaning and consistency of similarity measures (e.g., cosine similarity and Euclidean distance) across common NLP methods (e.g., n-grams and document embeddings) is unclear. This risks misalignment between theoretical constructs and textual measures, undermining the comparability of findings across studies. To address this gap, we review studies using textual similarity in organizational and psychological research, finding a jingle-jangle fallacy: identical labels are used for similarity estimates from different NLP methods, and different labels are used for the same method. Additionally, we examine the consistency of similarity measures across and within NLP methods. Different transformer-based embeddings’ similarity results are interchangeable. However, n-grams yield distinct, inconsistent results and are less appropriate for estimating similarity with distance measures. When applied to multi-word inputs, dictionaries and word embeddings return similar results reflecting linguistic style. We provide best practice recommendations and example code for operationalizing textual similarity, including clarifying which NLP methods correspond to content similarity, linguistic style similarity, and semantic similarity at the word, sentence, and document-levels of analysis.