Lesson 5

• Internal Validity is the ability to establish a causal relationship between a specified set of antecedent conditions and the subsequent behavior.
• Internal Validity is the called treatments
• External Validity is how well the findings of an experiment generalize or apply to people and settings that were not tested directly.
• Correlational study is one that is designed to determine the correlation (degree of relationship), between two traits, behaviors or events.
• Correlational Study may serve as a basis for a hypothesis.
• When two things are correlated, change in one is associated with change in another.
• Simple Correlations → Relationships between pairs of scores from each subject
• Pearson Product Moment Correlation (r) is the most commonly used procedure for calculating simple correlations
• Scatterplots also known as scatter grams or scatter graphs
• Scatterplots are visual representations of the scores belonging to each subject in the study.
• Outlier is an extremely atypical point located at a relatively long distance- an outlying distance from the rest of the coordinate points in a scatterplot
• ± .91 to 1.00 = Very strong/high
• ± .70 to .90 = Strong
• ± .30 to .69 = Moderate
• ± 00 to .29 = None/weak
• Positively/directly correlated = + 0.75
• Negatively/inversely correlated = - 0.75
• Positively correlated = When one variable increases, the other increases
• Negatively/inversely correlated

  When one variable increases, the other variable decreases
• Range truncation → An artificial restriction of the range of values of X and Y.
• Third Variable problem → An unknown or unmeasured variables affects the relationship between two variables.
• Linear Regression Analysis is when two behaviors are strongly related, the researcher can estimate on one of the measured behaviors from a score on the other.
• Multiple correlation → we can use this statistic to test the relationship of several predictor variables with a criterion variable
• Partial Correlation → This analysis allows the statistical influence of one measured variable to be held constant while computing the correlation between the other two
• Multiple regression → Used when more than two related behaviors are correlated, this can be used to predict the score on one behavior from scores on the others.
• Regression equation determine the weight (beta weights)of each predictor
• Pathanalysis is a correlation-based descriptive method used when subjects are measured on several related behavior.
• Pathanalysis is when the researcher creates models of possible causal sequences.
• Cross-Lagged Panel Design is the design uses relationships measured over time to suggest the causal path. Subjects are measured at two separate points in time on the same pair of related behaviors or characteristics.
• Quasi-Experimental Design - They can seem like a real experiment, but they lack one or more of its essential elements
• In Quasi, no control over who received treatment
• Ex PostFacto Design is a study in which the researcher systematically examines the effects of subject characteristics but without actually manipulating them.
• Ex PostFacto Design = “After the fact”
• Ex PostFacto Design is the researcher capitalizes of changes in the antecedent conditions that occurred before the study.
• Degree of manipulation and imposition of Ex PostFacto Design = Low-high
• True Experiment → Systematic difference between two people in different treatment conditions
• Ex Post Facto → Preexisting differences are manipulated and the effects they produce is measured
• True Experiment use random assignment of subjects.
• Non equivalent Designs is one in which researchers compares the effects of different treatment conditions on preexisting groups of participants.
• In nonequivalent designs, random assignment is not possible