Hypothesis Testing Basics
The hypothesis that states there is no effect or no difference.
What is the null hypothesis?
After converting scores to z-scores, the distribution has a mean of this value.
What is 0?
The hypothetical standard deviation of the sampling distribution of the mean.
What is standard error?
This test is used when the population standard deviation is unknown.
What is a t-test?
This statistic measures the average distance of scores from the mean.
What is standard deviation?
The probability of rejecting a TRUE null hypothesis.
What is Type I error?
Approximately this percentage of scores fall within ±1 SD in a normal distribution.
What is 68%?
Increasing sample size causes the standard error to do this.
What is decrease?
Compared to the z distribution, this distribution is more spread out when sample size is small.
What is the t distribution?
Cohen’s d is a measure of this concept.
What is effect size?
The probability of failing to reject a FALSE null hypothesis.
What is Type II error?
This statistic measures how far a score is from the mean in standard deviation units.
What is a z-score?
A study with this combination is most likely to reject the null: large sample size and ____ variability.
What is low variability?
A researcher predicts that a treatment will increase memory scores. This type of hypothesis test would typically be used.
What is a one-tailed test?
The probability of correctly rejecting a false null hypothesis.
What is statistical power?
When a test statistic falls into this region, the null hypothesis is rejected.
What is the critical region?
The natural difference between a sample statistic and the true population parameter due to random sampling.
What is sampling error?
This theorem explains the shape, central tendency and variability of the sampling distribution of the mean.
What is the Central Limit Theorem.
If t(28) = 3.21, p < .05 this is the number of participants in the sample.
What is 29?
An interval estimate constructed from sample data that is expected to contain the population mean with a specified level of confidence.
What is a confidence interval?
This decides how large the critical region is.
This law states that as sample size increases, the sample mean tends to get closer to the population mean.
What is the law of large numbers?
The distribution formed by taking the mean from every possible sample of a given size from a population.
What is the sampling distribution of the mean?
In a two-tailed z-test with α = .05, the critical values are approximately these two numbers.
What are ±1.96?
This measure of treatment magnitude stays the same whether the sample size is 25 or 400.
What is Cohen's d (effect size)?