In order to specify the ways in which traits are to be combined to predict any performance, Cattell developed the:

A researcher is investigating the effects of meditation on stress levels. Identify the independent and dependent variables in this experiment

a) The dependent variable is meditation; the independent variable is exercise. b) The dependent variable is stress levels; the independent variable is meditation. c) The independent variable is relaxation levels; the dependent variable is meditation. d) The independent variable is amount of stress; the dependent variable is meditation.

Dr. Muhammed wants to know if people will rate facial photographs more or less favorably based on the skin color and facial features of the pictures. He digitally alters photographs and mixes the features on each picture,

so that participants in his study do not know exactly what they are looking at. Keeping participants unaware of the exact nature of the study in which they are participating helps reduce __________ effects. a. criterion b. subject-expectancy c. placebo d. observer bias