After studying this chapter, students should be able to

• Propose conceptual, research, and statistical hypotheses
• List and describe the steps we follow to test a null hypothesis
• Discuss the implications of inferential error and statistical significance
• List, define, and provide the probabilities associated with the two types of inferential error
• Identify ways of increasing the power of the test of the null
• Discuss the importance of effect size and estimate the effect size for a given test of the null
• Describe the role of replication in research as it relates to power
• Define external and internal validity and discuss the influence of confounding and extraneous variables on inferential statements, including how to control such variables