BIOL 1010 Lecture Notes - Internal Validity, Random Assignment, Statistical Significance
Document Summary
When the sign of r is negative, variables are said to be negatively related as scores on one variable increase those for the other tend to decrease. Ex: # of hours spent watching t. v is negatively correlated with grade point average. Scatter diagrams of positive and negative correlations. In perfect relationships all points fall on a straight line. The values tend to scatter increasingly and become dispersed as the correlation becomes lower. When the correlation reaches 0. 00 knowledge of a persons score on one variable tells us nothing about his or her score on the other. The magnitude of a correlation coefficient tells us the strength of a relationship between two variables. Statistical significance refers to the likelihood that the results of an investigation are due to chance. A statistical significance correlation is one that is not likely to have occurred by chance.