Survey Design Class 02

 It is a true measure  Measurement Validity is the degree of fit between a construct and indicators of it.  It refers to how well the conceptual and operational definitions mesh with each others  The better the fit the greater the measurement

 When a researcher says that indicator is valid, it is valid for a particular purpose and definition. But less valid or invalid for others

 Questions about feelings toward school   Valid : for measuring morale among teachers   Invalid : for measuring morale of police officers

 (1)Face Validity  It is a judgment by the scientific community that the indicator really measures the construct

 Special type of face validity is the full content of a definition represented in a measure?   is the full content of a definition represented in a measure?

(1) Specify the content in a construct’s definition (2) Sample from all areas of the definition (3) Develop an indicator that taps all of the various parts of the definition.

 The validity of an indicator is verified by comparing it by another measure of the same construct in which a researcher has confidence

 (a) Concurrent: an indicator must be associated with preexisting indicator that is judged to be valid.  Example: Create a new test to measure intelligence.

 (b) Predictive: Indicator predicts future events that are logically related to construct. Example: the Scholastic Aptitude Test (SAT): to measure the ability of a student in college; if the SAT has high predictive validity, the students who get high SAT scores will subsequently do well in college.

 For measure with multiple indicators.  It has two kinds: (a) Convergent: Means that multiple measure of the same construct operate in similar ways

 (b) Discriminant: (Divergent Validity) It means the indicators of one construct are negatively associated with opposing construct.

 (1) Internal Validity: means there are no errors internal to the design of the research project High internal validity High internal validity means there are few errors

 (2) External Validity: It is the ability to generalize findings from a specific setting and small group to board range of setting and people High external validity High external validity means the results can be generalized to many situations and many groups of people.

 Statistical Validity: Means the correct statistical procedure is chosen and its assumptions are fully met