(9)Correlations vary in their Magnitude: an indication of the strength of the relationship between 2 variables. Indication of the strength of the relationship between 2 (or more) variables. Positive relationships: go in the same direction, an increase or decrease in one is related to an increase or decrease in the other(from the lower left corner to the upper right corner). Negative relationship:(upper left to the lower right) an increase in one variable is accompanied by a decrease in the other.(more of variable x means less of variable y). No relationship:the points are scattered randomly. Curvilinear Relationships: as a correlation coefficient of 0 means no relationship, it can also mean that there is curvilinear relationship(u-shape) Determined by correlation coeffiecient . Ranges from -1 to +1 – perfect, 0 – none.Strong.7 to 1 (pos or neg).Moderate .3 to .69.None to weak 0 to .29.Scatterplot:a figure the graphically represents the relationship between 2 variables. Causality:the assumption that a correlation indicates a causal relationship between 2 variables. Directionality: the inference made with respect to the direction of a causal relationship between 2 variables(assuming that one variable is the cause of another variable: illiteracy is the cause of drug use). Third-variable problem:the problem of a correlation between 2 variables being dependent on another (3rd) variable (hidden variable that). A way to test this 3rd variable problem is by using the Partial correlation:a correlational technique that involves measuring 3 variables and then statistically removing the effect of the 3rdvariable from the correlation of the remaining 2. Restrictive range:a variable that is truncated and has limited variability (range of window). Person-who argument:
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Causality, Scientific control, Controlling for a variable, Single Group Designs