In Susan Glaspell's Trifles, the men, representing society, assume that nothing Minnie Wright has gone through in her marriage could constitute a worthwhile reason for killing her husband. As the county clerk and Mr. Hale discuss the women's concern over losing a batch of preserves, the county clerk assumes Minnie will be found guilty. Mr. Hale assumes that the life of a woman on a farm is inconsequential: made up of unimportant tasks—
COUNTY ATTORNEY. I guess before we're through she may have something more serious than preserves to worry about.
HALE. Well, women are used to worrying over trifles.
When the women arrive, they don't initially see anything unusual, but they know what the men are looking for.
Mr. Henderson said coming out that what was needed for the case was a motive; something to show anger, or -- sudden feeling.
As they women step into the house, all seems (at first) as it should, and the women assume nothing will be found to incriminate Minnie Wright:
MRS. HALE. Well, I don't see any signs of anger around here…
However, after the women look closely, they find a birdcage with its door torn off its hinges, beaten up as if it had been attacked. At first they think something violent—like a cat—had destroyed the cage. However, there is no cat—there never has been one on the property. Soon, the women assume that Mr. Wright has killed the canary:
MRS. HALE. (jumping up) But, Mrs. Peters--look at it. Its neck! Look at its neck! It's all--other side to.
MRS. PETERS. Somebody--wrung--its neck.
(Their eyes meet. A look of growing comprehension of horror...)
As the women's eyes meet, their comprehension is based upon their assumption—their certainty—that Mr. Wright killed the bird.
The men assume that something will be found in the house to incriminate Minnie—so they have already assumed her guilt.
Like an Edgar Allan Poe mystery, the men also assume that nothing of importance takes place in a woman's life, aside from the comment about trifles—while all the time, exactly what they are looking for is right under their noses—but they ignore Mrs. Wright's domain in the home, assuming that women do little worth a man's notice (unless the men choose to criticize, as seen when the county attorney finds fault with the dirt on the kitchen towels). As the men prepare to leave, they are certain that nothing of any importance will be found in Minnie's things:
COUNTY ATTORNEY. You're convinced that there was nothing important here--nothing that would point to any motive?
SHERIFF. Nothing here but kitchen things.
The women assume that they have evidence the men can use in the form of the broken cage and the dead bird. Mrs. Hale also believes that the messy sewing in Minnie's quilt would prove to the men Minnie's poor state of mind—enough to convict her of murder. Mrs. Hale is so convinced, that she fixes the sewing—purposely destroying what she believes will be damaging evidence:
MRS. PETERS. Oh, what are you doing, Mrs. Hale?
MRS. HALE. (mildly) Just pulling out a stitch or two that's not sewed very good.
The men's assumptions hinder their investigation: the women's assumptions (and careful observations) protect Minnie from the men's eagerness to prove Minnie guilty under any circumstances.