A teacher at New Britain High School, decided to explore the…

A teacher at New Britain High School, decided to explore the effects of physical attractiveness on self-esteem. The teacher asked peers to rate the physical attractiveness of their high school classmates. Then, the teacher compared these ratings to a measure of self-esteem on record in the guidance office. It was noticed that those with the highest scores tended to have the highest self-esteem. Based on this information, which of the following would be the best conclusion?

To study the effects of REM (rapid eye movement) sleep on me…

To study the effects of REM (rapid eye movement) sleep on memory, researchers have participants try to memorize some material before going to bed in a sleep laboratory. Half of the participants are awakened repeatedly throughout the night whenever they enter REM sleep (depriving them of REM sleep), while the other half are allowed to go through REM sleep but are awakened an equal number of times in different sleep stages. In the morning, all participants memories are tested for the material they learned before bed. In this experiment, the independent variable is ________.