Ambiguity is closely related to paradox, or the idea that two contradictory facts are nevertheless true. For example, a reoccurring paradox occurs in Thorton Wilder's Our Town where the people of Grover's Corners are depicted as both insignificant and very important. The narrator quips that the town is less than average, then goes on to say the same sort of people as dwell in the town inhabited ancient Athens and Rome and Babylon. Rebecca later recalls a letter addressed to "Jane Crofut, The Crofut Farm, Grover's Corners, Sutton County, New Hampshire, United States of America [...] Continent of North America, Western Hemisphere, the Earth, the Solar System, the Universe; the Mind of God," which illustrates that Jane is both so small in the grand scheme of the universe and still part of the mind of God (46). This paradox comes to the forefront in the climax, where a dead Emily sees how precious and important every moment of life is and still chooses to forget her memories, as they are ultimately insignificant after death. Slice of life authors pepper their stories with paradox in order to examine the conflicting nature of the human condition--the ultimately paradox of being born knowing that we must eventually die.
Know what paradox is not? Hypocrisy. Hypocrisy is claiming to support one belief while actually subscribing to another--"do as I say, not as I do." While this centers on a contradiction, a paradox contrasts two contradictory facts or behaviors, while hypocrisy is a claim to act one way when the person acts purposefully in another way. Paradox is also not irony. Irony is when the opposite of what is expected occurs--in Our Town, there are foreshadowed hints around George that he may have an untimely death, so it's ironic when Emily is the one that dies. The only thing that conflicts in irony is the expectation of what will happen and what actually occurs. Here's another example: in Clerks, Dante both hates his job and derives pride from his work at the Quick Stop--that's a paradox. Yet when it comes to his love life, he is willing to cheat on Veronica to get back together with Caitlin, who broke his heart by cheating on him in high school--that's irony (oh, and Dante eventually comes to his senses when a character named Silent Bob gives him advice--more irony).