In Chapter 1 of Explorations in Poetics, Benjamin Harshav lays out his basic theoretical framework for literature. This frame is, I think, a particularly good starting point for modelling literary texts and mapping out their systems.
Within a text, he distinguishes between the Speakers, Internal Field of Reference (IFR), External Field of Reference (ExFR), referent (r; plural rs), and frame of reference (fr; plural frs). Overall, the IFR in the constructed fictional world within any text. Within the IFR exists both rs and frs. rs is anything which can be spoken of, real or non-existent, idea or event. frs are “any semantic continuum of two or more referents that we may speak about.” A fr has various kinds: unique description in time (“they used to eat”; “during the exciting birthday party last year) or general (“autumn”); real or non-existent. Moreover, frs within texts are sometimes indeterminate because they are not known or understood by the reader. At last, frs are what a text is about: as a network of references integrated into the broader IFR, they describe “what the text is about.” Meaning is also related to the EFR, though, namely “any FRs outside of a given text,” such as history or a philosophy. For example, when an authors claims that “on the 14th of August, PN1 spoke aggressively to PN2 in the streets of New York”, the text evokes the EFR, namely New York, and incorporates it into the IFR.
Concerning the relationship between IFR and EFR, Harshav comments on Tolstoy’s War and Peace: “to what extent Napoleon, as presented in the IFR, should be taken within the presented limits and to what extent the reader may, or should, draw on the Field of outside knowledge cannot be decided in advance, but has to be negotiated in an interpretation.” That is to say although Harshav distinguishes between EFR and IFR, the r or frs that are evoked by the IFR as originating from the EFR are subject to interpretation, in terms of how much of the r’s or fr’s world and characteristics should be drawn into the IFR from the EFR, even if absent in the IFR.
Undoubtedly, the ideas here are somewhat complex, simplified within this blog posts. What I want to point to is a few benefits of using Harshav’s theoretical framework. First, his framework is helpful for thinking about the relationship between a text’s fictional world (IFR) and the real world from which it draws material (EFR). As illuminated through his comment on War and Peace, though, the relationship between the EFR and IFR are subject to interpretation. Nonetheless, his framework at least provides clear domains which enables scholars to identify the fr in the EFR and IFR so that they can subsequently analyze the degree to which aspects of the fr in the EFR are evoked in the IFR. For Biblical Studies, this is related to the issue of historical context. That is, what sort of referents function as frames of reference within the fictional world of the literary text and to what degree does a literary text, such as Genesis 1, evoke and incorporate those frames of references and associated characterization from the EFR?
Second, Harshav’s model is helpful for identify the location wherein readers must place their own imagination into the texts. This occurs as a result of multiple frs being brought into tension with each other. Chapter Two, wherein Harshav discusses metaphors, is more clear on this point: readers must gap-fill when a frame of reference is mentioned. Naturally, this can vary in terms of what is evoked. For example, if a text says, “In the month of March,” the text may evoke distinct things for readers. For an individual in Washington, it may evoke weather which is rainy and around 50 degrees. For people living in other regions, though, the fr “March” may evoke other sorts of weather. At base, then, what is helpful is that Harshav’s theory and modelling of texts enables critics to more precisely identify where readers diverge on things evoked texts.
Finally, I have not yet finished Explorations in Poetics. I have no doubts, though, that Harshav’s other discussions will provide helpful theoretical foundations for analyzing biblical texts.
 Harshav (2008), 5.
 Harshav (2008), 39.
 Harshav (2008), 23.
 Harshav (2008), 27.