Σύγκριση μεθόδων

	Εξαγωγή λέξεων-κλειδιών	TF-IDF	Θεματική Ανάλυση
Πεδίο	Εξόρυξη Κειμένου	Εξόρυξη Κειμένου	Ποιοτική Έρευνα
Οικογένεια	Process / pipeline	Process / pipeline	Process / pipeline
Έτος προέλευσης	—	1988	2006
Δημιουργός	—	Salton & Buckley	Virginia Braun and Victoria Clarke
Τύπος	NLP text-mining task	Text vectorization / term-weighting scheme	Method
Θεμελιώδης πηγή	Mihalcea, R. & Tarau, P. (2004). TextRank: Bringing Order into Texts. EMNLP, 404-411.	Salton, G. & Buckley, C. (1988). Term-weighting approaches in automatic text retrieval. Information Processing & Management, 24(5), 513-523.	Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative Research in Psychology, 3(2), 77–101.
Εναλλακτικές ονομασίες	keyphrase extraction, key term extraction, Anahtar Kelime Çıkarma (Keyword Extraction)	term weighting, tf-idf weighting, TF-IDF Vektörizasyonu	TA, Reflexive Thematic Analysis
Συναφείς	4	3	3
Σύνοψη	Keyword extraction is a natural-language-processing task that automatically identifies the words or phrases that best represent the content of a document. It turns a body of free text into a compact, ranked list of key terms, drawing on statistical, graph-based methods such as TextRank (Mihalcea & Tarau, 2004), or embedding-based methods such as KeyBERT (Grootendorst, 2020).	TF-IDF, introduced by Salton and Buckley (1988), is a term-weighting scheme that scores each word in a document by how often it appears there and how rare it is across the whole collection. It turns raw text into weighted document vectors, giving high weight to terms that are frequent in one document but uncommon elsewhere.	Thematic Analysis (TA) is a qualitative research methodology for identifying, analyzing, and reporting patterns (themes) in qualitative data. Developed systematically by Virginia Braun and Victoria Clarke (2006), TA is flexible and accessible, applicable across diverse theoretical frameworks and data types, making it one of the most widely used qualitative methods in psychology, health research, and social sciences.