In selecting representative samples, the technique that specifies that the sampling frame is broken up into sub-groups before random selections are made is known as

Carrie is being held by her father. She is smiling at him one minute and then, unexpectedly, she slaps his face. This is a sign of which type of attachment?

insecure-avoidant disorganized secure-detached ambivalent

Interactions can only be detected in multifactor studies

Indicate whether the statement is true or false