The related samples t test can be conducted by finding, for each pair of scores, the differences between the scores and then conducting a one-sample t test of the null that the mean difference is zero.

A researcher conducts an experiment to establish a relationship between a chess player's mental stability and his performance in a game. He finds that the two have a Pearson product-moment correlation coefficient value of +1.00. This means the two variables—mental stability and performance—have a _____ relationship.

Fill in the blank(s) with the appropriate word(s).

Which of the following has research found hypnosis to be effective at treating or helping to treat?

A) Reducing depression B) Recovering memories C) Reducing habit disorders D) Reducing insomnia