Exam 2: Lectures 5-7 Flashcards
two-sample t-test
used to determine whether or not means on two independent samples from a normal distribution are equal or whether they differ
hypotheses for two-sample t-tests
π»_0: γππππγ_1 = γππππγ_2
π»_π: γππππγ_1 β γππππγ_2
Sensitivity analysis
to see whether the best decision changes as one or more inputs change
two sample t-test info
If we fail to reject null hypothesis (p-value β₯ .05),
If we reject null hypothesis (p-value < .05),
what assumption does a two sample t-test have?
that the variances of two groups are equal in the population
Observational study
analyze data already available to us
Designed experiment
control for various factors such as age, gender, or socioeconomic status so that we can learn more precisely what is responsible for the effects we observe
Null hypothesis for one-way ANOVA
there are no differences in population means across conditions
Alternative hypothesis for one-way ANOVA
at least one of them will be different
what is the analysis of variance (ANOVA)
The procedure for analyzing difference between more than two population means
experimental units
Entities measured at each treatment level (or combination of levels)
In ANOVA, what is the variable of primary interest that we wish to measure?
dependent variable
post hoc test
run to confirm where the differences occur between groups
Given the 0.05 significance level, please understand hypothesis testing with a given p-value
If p-value < .05 , then reject the null hypothesis
If p-value >0.05, then fail to reject the null hypothesis
decision tree
enables a decision maker to view all important aspects of the problem at once: the decision alternatives, the uncertain outcomes and their probabilities, the economic consequences, and the chronological order of events