Central Tendency
The middle score when values are arranged in order
What is the median?
This measure of variability is the difference between the highest and lowest test score in a dataset
What is the range?
This rule states that 68% of the data will fall within 1 standard deviation of the mean in a normal distribution.
What is the empirical rule or 68-95-99.7 rule?
What is zero?
This states that there is no change, no difference, or no relationship in the general population
What is the null hypothesis?
When using nominal scales or discrete variables, this would be the best choice of central tendency
What is the mode?
This measure of variability is often reported alongside the mean in psychology research to show how much scores differ from the average
What is standard deviation?
When finding probabilities under the normal curve, the total area is this
If a score is two standard deviations below the mean, the z-score would be this
What is -2.00?
The probability value that is used to define the concept or boundaries for "very unlikely" in a hypothesis test
What is alpha level or level of significance?
In reporting depression scores, a researcher chose this measure of central tendency instead of the mean because it is more resistant to outliers
What is the median?
What is the standard deviation?
What is sampling error?
This is the basic z-score formula
What is X-mu divided by alpha?
The name of the area of the distribution that means "reject the null hypothesis"
What is the critical region or rejection zone?
A set of anxiety scores is positively skewed. This measure of central tendency will be pulled upward the most.
What is the mean?
In the formula for sample variance, dividing by this value instead of n corrects for bias when estimating the population variance
What is n-1 or degrees of freedom?
A distribution of sample means is approximately normal if each sample is at least this big
If you want to find the probability for a score greater than (>) a z-score, you need to do this additional step to the probability value from the unit table
What is subtract from 1?
When a researcher rejects a null hypothesis that is actually true
What is Type I error?
In a histogram, this is on the y-axis
What is the frequency?
This is the numerator in the formula for variance
What is the sum of squares?
The standard deviation is the same as this if the sample is n=1
The z-scores associated with alpha = .05
What are -1.96 and +1.96?
What the Greek letter beta refers to
What is type II error?