The novel is structured in two distinct parts and within these parts into relatively short chapters.
The first part of the novel deals with Boo Radley, as Jem and Scout pursue a childish fascination with the reclusive neighborhood figure.
The children work throughout the first part of the novel to bring him out or to see him inside the house.
In this part of the novel, Harper Lee organizes nearly each chapter so that there is a distinct episode recounted and a conclusion offered. This strategy helps to create momentum in the narrative, establishing a sense that quite a bit is taking place in terms of action and character development.
The novel's second part concerns the trial of Tom Robinson, including the build-up to the trial and its aftermath. Chapters in this second part are not as universally conclusive. Some chapters create or explore problems that remain open (or open-ended) for some time.
In keeping with the larger themes of the second part of the novel, the chapters offer a parallel to the open-ended social conflicts that mar Southern society as the narrator, Scout, sees it. As a book of conscience, ultimately, the reader must draw her own conclusions regarding questions of race, justice, injustice, tolerance and intolerance.
Atticus hints at this ethic standing behind the more open-ended second part of the novel:
"The one thing that doesn't abide by majority rule is a person's conscience."