Correlational Research Strategy
Recall 5 basic Research Strategies
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Experimental
Nonexperimental
Quasi-experimental
Correlational
Descriptive
Correlational Research
• Goal is to establish associations or
relationships between variables
• No attempt at explaining relationship
– No manipulation
– Control
– Interfering of variables
• Nature of research is measurement of two
variables for each participant
Data for Correlational Study
• Scores from two variables, X and Y
• Graphed using a scatter plot
• Shows strength and type of correlation
– Closer data points to forming a straight line
stronger the relationship
– Direction of line indicates type
• Negativeas one increases the other decreases
• Positiveas one increases the other increases
Measuring Relationships
• Direction
– Positive and negative
• Form
– Linear and curvelinear
• Consistency
– +1.00-0—1.00
– Correlation coefficient
Application
• Prediction
– Example SAT and future GPA college
• Regression Analysis
– Using X scores (predictor variables) to predict Y
scores (criterion variables)
• Coefficient of Deterimination
– Proportion of variance accounted for