A successful strategy for preventing
vandalism, say the book's authors, is to fix the problems when they are small. Repair the broken windows within a short time, say, a day or a week, and the tendency is that vandals are much less likely to break more windows or do further damage. Clean up the sidewalk every day, and the tendency is for litter not to accumulate (or for the rate of littering to be much less). Problems do not escalate and thus respectable residents do not flee a neighborhood.
The theory thus makes two major claims: that further petty crime and low-level anti-social behavior will be deterred, and that major crime will, as a result, be prevented. Criticism of the theory has tended to focus only on the latter claim.