The most striking formal and technical characteristics of Tristram Shandy are its unconventional time scheme and its self-declared digressive-progressive style. Sterne, through his fictional author-character Tristram, defiantly refuses to present events in their proper chronological order. Again and again in the course of the novel Tristram defends his authorial right to move backward and forward in time as he chooses. He also relies so heavily on digressions that plot elements recede into the background; the novel is full of long essayistic passages remarking on what has transpired or, often, on something else altogether. Tristram claims that his narrative is both digressive and progressive, calling our attention to the way in which his authorial project is being advanced at the very moments when he seems to have wandered farthest afield.
By fracturing the sequence of the stories he tells and interjecting them with chains of associated ideas, memories, and anecdotes, Tristram allows thematic significance to emerge out of surprising juxtapositions between seemingly unrelated events. The association of ideas is a major theme of the work, however, and not just a structural principle. Part of the novel's self-critique stems from the way the author often mocks the perverseness by which individuals associate and interpret events based on their own private mental preoccupations. The author's own ideas and interpretations are presumably just as singular, and so the novel remains above all a catalogue of the "opinions" of Tristram Shandy.
Much of the subtlety of the novel comes from the layering of authorial voice that Sterne achieves by making his protagonist the author of his own life story, and then presenting that story as the novel itself. The fictional author's consciousness is the filter through which everything in the book passes. Yet Sterne sometimes invites the reader to question the opinions and assumptions that Tristram expresses, reminding us that Shandy is not a simple substitute for Sterne. One of the effects of this technique is to draw the reader into an unusually active and participatory role. Tristram counts on his audience to indulge his idiosyncrasies and verify his opinions; Sterne asks the reader to approach the unfolding narrative with a more discriminating and critical judgment.