Flashcards in Chapter 3 Deck (24):
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Variables
Something that varies
Has at least 2 levels
1
Constant
Something that could potentially vary but is kept the same for the study
2
Measured variable
The one whose levels are just observed and recorded
3
Manipulated variable
Researcher controls it
Certain variables cannot be manipulated like gender or iq
4
Conceptual variables
Abstract concepts such as shyness or. Intelligence
Also called a construct
Must be carefully defined at a theoretical level
5
Conceptual definition
The definition for a conceptual variable
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Operational variables
Turning a concept into a measured or manipulated variable
Gives the ability to test a hypothesis
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Claim
The argument someone is trying to make
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Frequency Claims
Describe a particular rate or degree of a single variable
Claim how frequent or common something is
Percentage of a variable
Number of people involved
Focus on 1 variable
Measured not manipulated
9
Association Claims
Argues one level of a variable is likely to be associated with a particular level of another
Correlate or covary
Contains 2 variables
Measured not manipulated
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Positive Association
High goes with high
Low goes with low
Positive correlation
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Negative association
High goes with low
Low goes with high
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Zero association
No association
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Causal Claim
Argues 1 of the variables is responsible for changing the other
Has 2 variables which covary
Goes beyond associations
Has 3 criteria
1- relationship between 2 variables not 0
2- causal variable must be shown to be first
3- no other explanation for the relationship
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Validity
Appropriateness of a conclusion or a decision
A valid claim
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Construct Validity
How well a conceptual variable operationalized
The extent to which the operational variables used in a study are a good approximation of the conceptual variables
Frequency Claim: how well did the researcher measure the variable?
Association Claim: how well did the researcher measure all the variables?
Causal Claim: how well has the researcher measured or manipulated the variables in the study?
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External Validity
The extent to which the results generalize to a large population or other times/ situations
Frequency Claim: How well the results of a study generalize to or represent people it context besides those in the study? How representative is the sample?
Association Claim: to what populations,settings, and times can we generalize this claim? How representative is the sample? To What other problems might the association be generalized?
Casual Claim: to what populations, settings, and times can we generalize the casual claim? How representative is the sample? How representative are the manipulations and measures?
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Statistical Validity
Addresses the strength of an effect and it's statistical significance. Also addresses the extent to which a study minimizes the prob of 2 errors: concluding that there is an effect when there isn't 1 ( type 1 error) or concluding there is no effect when there is 1 ( type 2 error)
Frequency Claim: what is the margin of error of the estimate?
Association claim: what is the effect size? How strong is the association? Is it statistically significant? If a relationship found what is prob of false positive (type 1) ? If no relationship what is prob of miss ( type 2)
Causal Claim: what is the effect size? Is there a difference between groups? How large? Statistically significant?
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Internal Validity
Is a relationship between 1 variable and another, the extent to which the first rather than a random variable is responsible for the second
Frequency claim: not relevant
Association claim: no causality asserted therefore not relevant
Causal Claim: was the study an experiment? Does the study achieve temporal precedence ? Does the study control for alternative explanations by randomly assigned participants to groups? Does the study avoid several internal validity threats?
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Independent variable
Manipulated variable
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Dependent variable
Measured variable
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What is needed to make a causal claim
Covariance
Temporal precedence
Internal validity ( third variable rule of confounds)
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What can help with a causal claim
An experiment where we control the IV to get temporal precedence and internal validity
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