CH 6

• Hypothesis


  An explanation of a relationship between two or more variables
• Experimental hypothesis


  A tentative explanation of an event or a behavior. It is a statement that predicts the effect of an independent variable on a dependent variable.
• Nonexperimental hypothesis


  Predicts how variables (events, traits, or behaviors) might be correlated, but not causally related
• Synthetic statement


  A statement that can be true or false
• A hypothesis must be a synthetic statement so that it can be assessed by gathering data that either support or contradict it
• Testability


  An experimental hypothesis is testable when it can be assessed by manipulating an IV and measuring the results on the DV
• Without testability, we cannot evaluate the validity of a hypothesis
• Parsimony


  Preferring a simple hypothesis over one requiring many supporting assumptions
• A simple hypothesis allows us to focus our attention on the main factors that influence our dependent variable
• Inductive model of formulating a hypothesis


  1. Reasoning from specific cases to general principles to form a hypothesis

  2. Researchers use inductive reasoning to construct theories by creating explanations that account for empirical data (observations)
• Deductive model of formulating a hypothesis


  1. Reasoning from general principles to specific predictions

  2. This approach is used to test the assumptions of a theory
• Combining induction and deduction


  1. Develop propositions using induction by examining specific cases

  2. Make predictions using deduction
• Combining induction and deduction

  • Walster et al. formulated equity theory based on specific observations (induction) and then tested predictions from this theory (deduction)
• Building on prior research


  Reviewing research that has already been published, both experimental and nonexperimental studies
• How reviewing prior experiments helps develop a hypothesis

  • Identifies questions that have not been conclusively answered or addressed at all
  • Suggests new hypotheses
  • Identifies additional variables that could mediate an effect
  • Identifies problems other researchers have experienced
  • Helps avoid duplication of prior research when replication is not intended
• Serendipity and the windfall hypothesis


  A scientist who is open to unexpected results and sufficiently informed can understand the significance of unexpected findings, while a dogmatic scientist would be less likely to "see" or appreciate the significance of serendipitous events
• Intuition


  Knowing without reasoning, or unconscious problem-solving. Intuition guides what we choose to study in an experiment, but must be directed by our literature review
• Strategies for developing experimental hypotheses when all else fails

  1. Read an issue of a psychology journal

  2. Observe how people behave in public places

  3. Choose a real-world problem and try to identify its cause
• Purpose of the Introduction section of an APA-format paper


  Provides a selective review of research findings related to the research hypothesis, and identifies which questions have not been definitively answered by previous studies
• Meta-analysis


  A statistical analysis of many similar studies that measures the average effect size of an independent variable across studies with similar methodologies, helping establish the strength and external validity of a causal relationship