Final answer:
Karlene should place her 4-year-old daughter in time-out for four minutes, following the guideline of one minute per year of age for behavior modification.
Step-by-step explanation:
Karlene, when using the suggested time-out technique for behavior modification, should set the time-out period based on her daughter's age. According to the general rule of thumb for time-outs, the length should be one minute for each year of the child's age. Since her daughter is four years old, the appropriate time-out duration would be four minutes. This technique is effective when the child is removed from a desirable activity and placed in a less desirable location to decrease the unwanted behavior. It is important to set a timer to let the child know the duration of the time-out and to remain calm and consistent with the practice. After the time-out, providing a hug or a kind word can help maintain a positive parent-child relationship.