Chapter 7 Flashcards
Categories, rules reliability applied > results increase valid
Valid> fact or evidence?
Valid> speakers logic is persuasive
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Social science
- Breaks reality into distinct parts we believe exist and have observable indicators.
- Social science operates with logic and properly collected observations to connect those concepts to help predict, explain and control reality.
CA
Scholars must address a concept they defined about communication reality exists in reality / is it the appropriate measurement?
Second issue
Linking concepts through data collections and analysis methods with producing successful predictions.
CA: reality of communication in our world.
= creation of reliable and valid categories making up the variables we describe and relate to one another in hypothesis or models of communication processes. Operationalise define content categories to terms of these in hypothesis and questions.
When asking about validity>
Operational definition that reduces ambiguity in measurement of communication reality rather than apprehended reality
Resolving ambiguity
Connecting content measurements to previous research.
Critical problem: efforts to achieve reliability in content category measures.
Measurement reliability
Necessary but not sufficient condition for measurement validity.
Measure
Can be reliable in application but wrong in really measuring: valid must be both reliable in application and valid for what it measures.
Special issue
Reliable measures can come at expense of valid measurement.
Get high levels of coder agreement: operational definition may have only tenuous connection with the concept of interest.
Computer CA:
Validity of concepts compromised by the focus of keywords absent any context that gives them meaning. Solution: multiple measures of concept - meaningful beyond the study?
Tests of Measurement Validity
Four tests - operational terms we use in our hypotheses and questions. Tests of validity apply to measures, constructs and relationships
Face validity:
Most common, persuasive argument that a measure of a concept makes sense on its face. Obvious to all and no additional explanation.
Good when agreement is high. Enhance face with precious measurements.
Can be chancy - concept can have latent meanings - same concept in different ways.
Concurrent validity:
Two different methods and same conclusion. Face validity strengthened: correlate the measures used in one study with a similar in another study. two methods provides mutual or concurrent validation
Predictive validity:
Correlates a measure with some predicted outcome. If outcome occurs as expected: confidence in the validity of the measure increases. Prediction borne out: confidence in the validity of measures making up operational decisions strengthens.
Validating the predictive power of the content model
Construct validity:
Relation of an abstract concept to the observable measures that indicate the concepts existence and change, construct exists but not directly observable except through one or more measures.
Change in underlying concept will occur change in measure.
Stat tests: relate to only that concept and no other?
- con. validity does not exist: measures may change because of their relation to some other concepts.
When varying: only concept of interest varies. (confident in that.
= present if the measurement instrument does not relate to other variables when there are no theoretical reasons to expect it.
IF researchers find a relation between a measure and other variables predicted by theory and fail to find another one (not predicted by theory) = evidence for construct validity.
Common constructs across studies for coherence and common focus.
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Validity in Observational Process
How to link them in a way: validly describes social reality. Minimise human biases
Random sampling, randomly assigning to create control
In CA: How to use protocol definitions and tests for chance agreement to minimise the influence.
HOW CA ACHIEVES this
Internal and external validity
Internal validity:
Ability of an experiment to illuminate valid causal relations. (controls to rule out influence).
External validity:
Broader relevance of an experiment’s findings to the causal relations in the world. Natural settings in experiments makes this better.
CA: cannot possess internal causal validity since it cannot rule out all known and unknown third variables. Causal: time order
CA: strengthen ability to make casual inferences with CA paired with survey research to explore relations.
CA can be very strong in external validity and generalisability
External and notion of social validity=
Social significance of content and relevance and meaning.
Internal Validity and Design
CA: illuminate patterns, regularities, or variables relations.
CA alone cannot establish antecedent causes producing those patterns in the content or explain as causal the subsequent effects that content produces in the social system.
CA: should
Address issues of control, time order and correlation of variables included in a causal model