Research Methods: Chapters 11 Flashcards
What is Internal Validity?
- Did I eliminate other variables?
- Am I studying what I set out to study?
- Are my methods appropriate?
What is a threat to Internal Validity?
Something that could negatively impact internal validity?
What is History in terms of a threat to Internal Validity?
A major event that happened during your study that could alter your data/results.
What is Maturation in terms of a threat to Internal Validity?
Maturing, growing, or learning, which may alter your data/results.
Explain Statistical Regression (regression to the mean), Testing, Instrumentation, Selection, and Mortality (attrition) in terms of a threat to Internal Validity?
- Statistical Regression: When a group average (mean) is unusually extreme at Time 1, the next time that group is measured (Time 2), it is likely to be less extreme - closer to its typical or average performance.
- Testing: A specific kind of order effect, referring to a change in the participants as a result of taking a test (dependent measure) more than once. People may have become more practiced at taking the test, leading to improved scores over time. Testing threats include practice threats.
- Instrumentation: Occurs when a measuring instrument changes over time. Changes in machinery or observer criteria.
- Selection: A bias that occurs when participants in different groups of a study are not comparable at the outset, potentially leading to inaccurate conclusions about the effect of a treatment or intervention.
- Attrition: When participants are no longer able to be a part of the study. This becomes an issue to Internal Validity when attrition is systematic: a particular subset of people drops out of the study.
What is Observer Bias?
Observer Bias occurs when researchers’ expectation influence their interpretation of the results.
What is a double-blind study and a masked design?
- A double-blind study is when neither the participants nor the researchers who evaluate them know who is in the treatment group and who is in the comparison group.
- A masked design is when the participants know which group they are in, but the observers do not.
Explain the Placebo Effect.
Occurs when people receive a treatment and really improve, but only because the recipients believe they are receiving a valid treatment.
Explain a double-blind placebo study.
When neither the participants nor the observers know which participant is in the real group or the placebo group.
What is a null effect?
When the independent variable did not make a difference in the dependent variable; there is no significant covariance between the two.
What is noise?
When there is too much unsystematic variability.
Explain what a measurement error is.
When a human or instrument factor inflates or deflates a person’s true score on the dependent variable, leading to high within-group variability.
Explain individual differences.
The variations and unique characteristics that distinguish one person from another, encompassing areas like personality, intelligence, abilities, and behavior. Individual differences can alter the variability of a study because they may naturally have higher or lower scores.
What is situation noise?
External distractions create unwanted fluctuations in the data, obscuring the real relationship between variables or leading to inconsistent judgments.
What is power?
The likelihood that a study will return a statistically significant result when the independent variable really has an effect.
