Hypotheses & Errors
This hypothesis states that at the population level, the explanatory variable has no effect.
Answer: What is the null hypothesis?
This test is used when the population standard deviation is known.
Answer: What is a single-sample z test?
The notation for the standard error of the mean is this.
Answer: What is σM?
When a sample value is greater than the population value, this type of sampling error has occurred.
Answer: What is positive sampling error?
Large values of t are used to make this decision about the null hypothesis.
Answer: What is reject the null hypothesis?
The probability of committing a Type I error is also known as this.
Answer: What is alpha (α)? or false positive
This test compares a sample mean to a known population mean when the population standard deviation is unknown.
Answer: What is a single-sample t test?
The mean of the sampling distribution of the mean equals this.
Answer: What is the population mean?
When researchers rely on college students as participants, they are using this type of sample.
Answer: What is a convenience sample?
Setting alpha before analyzing data helps researchers do this.
Answer: What is know the decision rule before reaching a choice point?
Failing to reject the null hypothesis when it is actually false is called this.
Answer: What is a Type II error? or false negative? or beta?
This type of t test is used when comparing pretest and posttest scores from the same participants.
Answer: What is a paired-samples (dependent-samples) t test?
M ± 1.96σM represents this.
Answer: What is the 95% confidence interval for the population mean?
Interviewing siblings together in the same room violates this assumption.
Answer: What is independence of observations?
For a two-tailed test with alpha = .05, the rare zones are located in these areas of the distribution.
Answer: What are the upper and lower 2.5% (0.025 in each tail)?
If a researcher rejects the null hypothesis but should not have, this error has occurred.
Answer: What is a Type I error? or alpha? or a false positive?
When calculating an independent-samples t test, the difference between means is divided by this.
Answer: What is the standard error of the difference?
In a 95% confidence interval, the brackets extend this many standard errors from the sample mean.
Answer: What is 1.96 standard errors?
Testing the same participant twice in a single-sample t test violates this assumption.
Answer: What is independence of observations?
The critical value of t depends on alpha level, whether the test is one- or two-tailed, and this.
Answer: What is degrees of freedom (or sample size)?
The probability of rejecting the null hypothesis when it should be rejected is known as this.
Answer: What is power?
In an independent-samples t test, the symbol used to represent the sample size for each group is this.
Answer: What is n?
Daily Double!
If a researcher rejects the null hypothesis using a single-sample t test, the confidence interval provides an estimated range containing this.
When data are positively skewed, this assumption of the single-sample t test is most likely violated.
Answer: What is the assumption of normality?
The critical value of t is best defined as this.
Answer: What is the cutoff point for determining whether to reject the null hypothesis?