Statistical Significance

1. Statistical Significant-A statistically significant outcome indicates that the differences between sample means probably did not occur by chance.

2. Type I Error-Concluding that a statistically significant result indicates a difference in population means when the result is actually due to chance.

3. Type II Error-Accepting the null hypothesis when in fact the null hypothesis is false.

Problems With Significance Testing

1. The criterion for a statistically significant result is arbitrary.

2. The likelihood of a statistically significant outcome increases as a function of sample size.

3. A foolish investigator might interpret a nonsignificant result as no result.

Beck’s Opinion

1. Both test of statistical significance and effect size are important and provide useful information.

1. Therefore, you should assess both measures of statistical significance and effect size.

Bivariate Correlations

1. Bivariate correlation-The statistical relationship between two variables.

2. Correlations range between -1 and +1.3. Correlations may be negative, positive or

zero.4. The absolute value of the number indicates

the strength of the correlation.5. The sign, plus or minus, indicates the

direction of the correlation.

A Few Ethical Issues

1. Truthfulness-Scientists depend on the honesty of other scientists.

2. Three cases in which deception is considered ethical.a. Participants have given “informed consent.”b. Deception does no harm.c. Research cannot be performed without deception.

The Trait Approach

1. Trait-A relatively stable and long lasting personality attribute.

2. Some traits are introversion, ego control, neuroticism, and grade-orientation.

3. Almost all the research on traits is correlational.

4. Trait research focuses almost exclusively on individual differences.

Person-Situation Debate

1. Person-situation debate-Which is more important in determining behavior, the person or the situation.

2. Mischel’s view-Behavior is too inconsistent to allow behavior to be characterized in terms of personality traits.

3. Mischel contended that correlations between traits and behavior tend to be less than .30.

4. Nisbett contended that correlations between traits and behavior tended to be less than .40.

Response To Mischel-Nisbett

1. Unfair literature review-Contends Mischel selected poorly conducted studies.

2. Personality research can be improved.

3. A correlation of .40 is not trivial.

How To Increase The Correlation Between Personality Measures And Behavior

1. Measure behavior outside the laboratory.

2. Check for moderator variables.

3. Predict behavior trends rather than individual actions.

A Summation

1. Research on situational variables is concerned with how people act under specific circumstances.

2. Research on personality traits is concerned with how people act in general.

3. There is no doubt that both personality and situational variables affect behavior.

4. Therefore, in your instructor’s opinion arguing which is most important is usually a silly waste of time.