PS102 Chapter Notes - Chapter 2: Statistical Significance, Descriptive Statistics, Standard Deviation
Document Summary
Psychologists use statistics to describe and measure relationships between variables. Correlation: a predictable relationship between two or more variables. Correlation coefficient: describes relationship of correlations, especially in descriptive studies. Number itself and the positive or negative sign each convey information. Negative or positive sign tells you direction of relationship. When scores on both variables get bigger together, relationship is positive correlation. One variable increases as another decreases = negative correlation. Number tells the size/strength of relationship between cvriables. The tighter packed data cloud in graph appears to be. Correlation of 0 means there is no linear relationship. Farther correlation coefficient gets from 0, the stronger the relationship between the two variables. Correlation of -1 or +1 is a perfect correlation. We do not see perfect correlations often causality: whether or not a change in one variable actually causes a change in the other. Experimental analyses: examining differences between groups and determining the cause of such differences.
