This post is part of an ongoing series formulating a methodology for tracking and understanding the variety of ways in which early Christians received and utilized Scripture.
Genre: Consideration of genre similarly affects a historical-critical methodology, especially when the texts analyzed belong to two different genres of literature or the pericope in question comes in a genre different than the rest of that in which it appears. For instance the Odes of Solomon, by nature of their composition as liturgical verse, were crafted quite differently than prosaic pieces of Christian literature from the same period. While a parallel term such as “living water” (Ode 6:18) might not suggest, for example, that the prose of the Epistles of Ignatius relied upon the Gospel of John, in a poetic work such as the Odes—which must deal in composite and stylistic elements—the Odist might only reveal his reliance on that Gospel through use of a particular term like “living water.”
Language: The language criterion draws attention to transformations of language which occur when texts or traditions traverse linguistic boundaries. Translation is never a one-for-one process, suggesting that translation and interpretive differences might mask instances of literary connection across linguistic boundaries. If, for instance, the Gospel of Thomas was written in Greek and then translated into Coptic, we would expect to find more significant overlaps with the canonical gospels than if Thomas was composed in Coptic from the start.
 Carol A. Newsom, “Pairing Research Questions and Theories of Genre: A Case Study of the Hodayot,” Dead Sea Discoveries 17 (2010): 271-6. When discussing genre (and especially different genres) we must be careful not to reify the concept. Carol Newsom has helpfully articulated six major ways of understanding genre–as classificatory boxes, in accordance with family resemblance theory, as modes of comprehension, by focusing on communicative roles, as modes of perception, and as social functions–and each of these models may fruitfully be deployed (even in combination) when discussing the impact of cross-genre and intra-genre textual borrowings. See also Alastair Fowler, Kinds of Literature: An Introduction to the Theory of Genres and Modes (Cambridge: Harvard University Press, 1982), 36. Pavel N. Medvedev, The Formal Method in Literary Scholarship A Critical Introduction to Sociological Poetics (trans. A. Wehrle, Baltimore: Johns Hopkins University Press, 1978), 133. James L. Kugel, Traditions of the Bible: A Guide to the Bible As It Was at the Start of the Common Era (Cambridge: Harvard University Press, 1998), 23-6. James H. Charlesworth, Critical Reflections on the Odes of Solomon: Volume One: Literary Setting, Textual Studies, Gnosticism, the Dead Sea Scrolls and the Gospel of John (Sheffield: Sheffield Academic, 1998), 233.  See Simon J. Gathercole, The Composition of the Gospel of Thomas: Original Language and Influences (Cambridge and New York: Cambridge University Press, 2012).