1. Methodology
Week 5

2. Objectives Quizzes and assignments review
Discuss the methodology design and elements
Define validity and its types
Define reliability and compare to validity

3. Quizzes and assignments
Quiz 3 was due today
Introduction assignment due today
Lit review assignment is due next week
Proposal assignment graded

4. Methodology Population: to determine the sample and sample size
Instrument:
tool used to collect the data
Experimental procedure:
protocol
Data collection: answer the questions “What”:
What data will be collected, what variables are involved, etc.
Data processing and analysis

5. Methodology Statistical analysis: T-test, ANOVA, etc.
Validity and reliability

6. Validity Internal validity External validity
Internal validity refers to the condition that observed differences on the dependent variable are a direct result of manipulation of the independent variable, not some other variable.
External validity
External validity refers to the condition that results are generalizable, or applicable, to groups and environments outside of the experimental setting. Can findings be generalized back to the population?

7. Content Validity
This approach measures the degree to which the test items represent the domain or universe of the trait or property being measured.
Subjective measure of how appropriate the items seem to a set of reviewers who have some knowledge of the subject matter

8. Construct Validity
A construct is defined as a property that is offered to explain some aspect of human behavior, such as mechanical ability, intelligence, etc
First the researcher must develop the definition of a meaningful, useable construct
Next, the adequacy of the test used to measure it must be evaluated

9. Criterion Related Validity
The ability to detect the presence or absence of one or more criteria considered to represent traits or constructs of interest

10. Reliability Consistency in results or measures
The degree of stability exhibited when a measurement is repeated under identical conditions
Must prove reliability before one can prove validity
A lack of reliability may arise from divergences between observers or instruments of measurement or instability of the attribute being measured

11. Test-retest
Examines the consistency of the responses between two tests

12. Alternate-form reliability
Use differently worded forms to measure the same attribute
Questions or responses are reworded or their order is changed to produce two items that are similar but not identical

13. Split-halves Method
In the split-halves method, the total number of items is divided into halves, and a correlation taken between the two halves.