Research Methods in Psych Exam 1 - Ch 3

Variables

something that varies, must have two levels/conditions/values

Level of a variable

has to have at least two levels

Measured variables

levels are simply observed and recorded

manipulated variable

what is changed or controlled in a study

Constant

something that could potentially vary but that has only one level in the study in question

Conceptual variable

abstract, theoretical concepts; also called constructs and conceptual definitions

ex: spending time socializing

Operation

to turn a conceptual defintion into a measured or manipulated variable

ex:how often somone socializes with friends

Frequency claim

describes a particular rate or degree of a single variable

ex: 4 out of 5 dentists recommend trident or middle school studetns see 2 to 4 alcohol ads a day

Association claim

argues that one level of a variable is likely to be associated with another level

ex: peoplewith high incomes spend less time socializing

Causal claim

one of the variables is responsible for changing the other

ex: music lessons inhance IQ, music lessons may inhance IQ

Correlate

when one variable changes, the other variable tends to change, too

Correlational study

the variables are measured and the relationship between them is tested; can support an association claim

Positive correlation

high goes with high and low goes with low

negative correlation

high goes with low and low goes with high

zero correlation

no association between the variables

Validity

appropriateness of a conclusion or decision

Construct validity

how well a conceptual variable is operationalized

Generalizability

the extent to which the subjects of a study represent the population

External validity

how well the results of a study generalize to, or represent, people or contexts besides those in the original study

Statistical validity

the extent to which the data support the conclusion

Margin of error of the estimate

confidnece interval; a range designed to include the true population value a high proportion of the time

Type 1 error

when nothing is there based on the entire pop. but the research saw something in the conclusion

Type 2 Error

when something is therebut the research doesn’t see anything

Covariance

the extent to which two variables are observed to go together, is established by the results of a study

Temporal precedence

the method was designed so that the causal variable clearly comes first in time, before the effect variable

cause comes before effect

Internal validity

can elimainate alternative explanations