Definitions
This measure of spread is based on the middle 50% of the data
What is the interquartile range?
The statistic used for comparing two means from independent samples
What is the two-sample t-statistic?
This hypothesis states there is no relationship between variables
What is the null hypothesis?
This type of variable has categories with no inherent order
What is a nominal variable?
A p-value = .47. At α = .05, what is the correct decision?
What is reject the null hypothesis?
The value used as a cutoff for statistical significance
What is the alpha level?
The statistic used to test differences among three or more means
What is the F-statistic (ANOVA)?
If p < α, this is the correct conclusion about H₀
What is reject the null hypothesis?
This level of measurement includes ordered categories
What is an ordinal variable?
The 95% CI for a mean difference is [−1.2, 3.8]. Is the result significant?
What is No?
The theoretical probability distribution of all possible sample values for the statistics in which we are interested
What is the sampling distribution?
The statistic that tests whether two categorical variables are related
What is the chi-squared statistic?
This value represents the probability of getting your result if H₀ is true
What is the p-value?
This type of variable has only two categories
What is a binary (or dichotomous) variable?
A t-test output shows t=0.82. What can we conclude?
What is fail to reject the null hypothesis?
A set of assumptions and propositions used to explain, predict, and understand social phenomena
What is a theory?
The statistic used when the population standard deviation is unknown
What is the one-sample t-statistic?
The value that defines the critical cutoff on a test distribution and determines the rejection region for a hypothesis test
What is the critical value?
This is the variable that is hypothesized to cause change
What is the independent variable?
The correlation coefficient is r = −.72. Describe the relationship.
What is a strong negative relationship?
This term describes a relationship that disappears when a control variable is added
What is spuriousness?
The statistic used to estimate how many standard deviations a value is from the mean
What is the z-statistic?
This distribution is used when sample size is small and σ is unknown
What is the t-distribution?
This type of numeric variable can take only whole-number values and is often produced by counting rather than measuring
What is a discrete numeric variable?
A correlation analysis reports r = .08, p = .62, n = 450. How should this result be interpreted?
What is: there is a very weak, non-significant positive relationship; we fail to reject the null hypothesis?