- must translate concepts into form in which they are measurable
Clarifying the Concepts
- concept – abstract summary of whole set of behaviours, attitudes and characteristics à with something in common
- define concept, then develop indicators for concept as it has been defined.
- how to clarify concepts
o obtain a range of definitions of the concept.
o identify common elements
o develop definition based on these
o or
o distinguish between different ways concept has been used
- decide on a definition
o justify decision
o to assign definition à give it nominal definition / working definition
- delineate the dimensions of the concept
o eg, social , political, psychological, etc
o concept mapping
Developing Indicators
- descending the ladder of abstraction
- sub dimensions
- to develop indicators
o how many indicators to use
o how to develop the indicators
o how to form items into a questionnaire
- how many indicators to use
o if no agreed way of measuring a concept, develop indicators for range of definitions
o if concept is multidimensional, are you really interested in all dimensions
o ensure key concepts are thoroughly measured
o number of questions to capture scope of concept
o pilot test to eliminate unnecessary questions
o practical considerations – eg, overall length of questionnaire
- how to develop indicators
o where possible, use well established indicators
o some groups – use a less structured approach to data collection
o use informants
Evaluating Indicators
- reliability
o obtain same result on repeated occasions
o sources of unreliability
§ bad wording of question
§ interviewer effect
§ coding error
§ questions on which respondent has no opinion
o testing reliability
§ best methods only apply to measuring reliability of scales where we have a set of questions to measure one concept – rather than single item indicators
§ single question to measure concept
· test – retest method
o increasing reliability
§ use multiple item indicators
§ careful question wording
§ interviewer training
§ working out coding methods
- validity
o measures what it is intended to measure
o not the measure à use to which measure is put
o criterion validity
§ compare how people answered our new measure of concept, with existing well accepted measures of concept.
· assume existing measure is valid?
§ criterion groups
· eg, new measure of political conservatism given to members of both conservative and radical groups
o content validity
§ eg, test of arithmetic ability
o construct validity
§ how well measure conforms with theoretical expectations
- problem of meaning
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