Descriptive Statistics
When the mean, median, and mode are all equal.
What is a normal distribution?
Also referred to as categorical or qualitative scales.
What are nominal scales?
The variable that the researcher manipulates.
What is the independent variable?
Hypothesis stating the finding of "no difference"
What is the Null Hypothesis?
When research participants behave differently because they know they are being observed.
What is the Hawthorne effect?
One example is the mean or average score.
What are measures of central tendency?
A ranking scale (like a rubric) that appears to be equal across ranks but is not.
What is an ordinal scale?
The construct that is measured, or the construct under study.
What is the dependent variable?
To reject the null when you should not have rejected it.
What is Type I error?
"Type" of validity having to do with generalization of research results to a larger population
What is external validity?
A frequency distribution that has "twin peaks."
What is a bimodal distribution?
Scale with equal intervals but no true zero.
What is an interval scale?
Type of design that randomly assigns intact groups into control or treatment conditions.
What is quasi-experimental design?
An effect from a study (e.g., p < .05) that is not likely due to chance.
What is statistical significance?
Strength of your research design supports confidence in your results (your findings are defensible)
What is internal validity?
The statistic that provides information about the variance of scores in a sample.
What is the standard deviation?
This scale has similar properties to an interval scale but it also has a rational zero point.
What is a ratio scale?
The relation between two quantitative criterion variables
What is a correlation study?
Collecting a random sample whose subgroups are relative in size to the population's subgroups.
What is proportional stratified sampling?
Uncontrolled problem variables in experimental designs.
What are confounding variables?
Credited with developing the pie chart.
Who is Florence Nightingale?
(∑x)2
What is the squared sum of the set?
Variation (or error) in the dependent variable that is not due to the independent variable.
What is measurement error?
Having a large enough sample size to confidently reject the null when it is indeed false.
What is statistical power?
10 for each group; 30 overall
What is minimum sample sizes for inferential statistics?