Selection of research participants - only those who can be measured by the variables being investigated. Data collection - must be in quantifiable form. Interpretation One problem with interpretation is the shotgun approach which is when a large number of variables are measured and analyzed without a justifiable rationale for their inclusion. This approach can lead to inconveniencing participants and higher expenses for the time and number of measuring tools or methods. Correlations do not establish cause and effect relationships between variables.
Correlations break down complex relationships into simpler components.
Statistical Factors in Prediction Research Group Prediction Prediction research is useful for practical selection purposes. This is the tendency for predictive validity to decrease when a research study is repeated. Correlation Ratio, eta This computation is used when the relationship between two variables is non-linear. Adjustments to Correlation Coefficients Correction for Attenuation Provides an estimate of what the correlation between the variables would be if measures had perfect reliability. Correction for Restriction in Range Applied when researcher knows that the range of scores for a sample is restricted on one or both of the variables being correlated.