A prediction is allowed to change
Keep Book Predictions Separate from Facts
Label the theory as a guess, record what the page actually shows, and leave your first note intact. Add a separate update only when you reach new evidence. The gap between those notes is part of the reading experience.
A convincing theory can feel like something the book has already told you. After a break, that makes it easy to remember an inference as a fact. A small split card preserves both the clue and the meaning you gave it at the time.
Before looking ahead
Put the page beside the guess
Write one theory in your own words, starting with “I think” or “Maybe.” Add the chapter and page you have reached. This records what you suspected then; it does not claim that the story has confirmed it.
Separate the evidence
What does the page actually show?
On the next line, note one observable detail without adding a motive. “The letter is missing” and “the neighbor took the letter” are different kinds of notes. The second is still a guess unless the book has established it. This is an invented example, not a claim about a particular novel.
Leave room
An unanswered question can stay unanswered
Do not search a character wiki or later summary to settle the theory. Write what would change your mind, then return to your current page. You do not need to predict correctly for the card to be useful.
When the book reveals more
Add an update without rewriting the old note
Give the new evidence its own page reference. Mark the earlier theory as supported, contradicted, or still open. Keep the original wording legible so a later reread does not erase how the uncertainty felt.
At a discussion
Keep later updates behind the agreed page limit
If a reading group has not reached your update page, share only the earlier question and its location. Keep the later answer private. A label is a reminder for the reader; it is not an automatic spoiler filter.
Stop rule
One theory is enough
Use the card for a question you actually want to return to. Skip details that do not matter to your reading. A list of every possible suspect or outcome can become more work than the book itself.