Variables
This type of variable consists of categories with no inherent order.
What is nominal?
This sampling method uses whoever is easiest to recruit.
What is convenience sampling?
This measure of center is most affected by outliers.
What is the mean?
The formula for a z-score.
What is z = (X – M)/SD?
This acronym helps you remember the correct order for solving math problems.
What is PEMDAS?
Height, reaction time, and weight are examples of this type of variable. (can be meaningfully divided into smaller and smaller parts)
What is continuous?
This sampling method gives everyone an equal chance.
What is simple random sampling?
This measure represents the middle score.
What is the median?
After all scores in a dataset are converted to z-scores, this are the new mean and standard deviation.
What are 0 and 1?
(Mean = 0, SD = 1)
A value that describes a population, rather than a sample, is called this.
What is a parameter?
A Likert scale measuring agreement from “strongly disagree” to “strongly agree” is conceptually this scale.
What is ordinal?
This sampling method ensures key subgroups are represented.
What is stratified sampling?
The most frequently observed score in a distribution.
What is the mode?
A positive z-score tells you that a score falls in this location relative to the mean.
What is above the mean?
A distribution with very tall, narrow peaks is described using this term.
What is leptokurtic?
This scale has equal spacing and a true zero.
What is ratio?
The natural difference between a sample statistic and a population parameter.
What is sampling error?
This statistic is the average distance from the mean.
What is standard deviation?
Approximately this percentage of scores in a normal distribution fall within one standard deviation above or below the mean.
What is 68%?
This Greek letter represents the population standard deviation.
What is sigma (σ)?
The variable that is manipulated in a research study.
What is independent variable?
This is a non-experimental research method that measures the statistical relationship between two or more naturally occurring variables without manipulating them.
What is correlational research?
In this type of distribution, most scores are high, but a few very low scores pull the tail to the left.
What is negatively skewed?
A dataset has a mean of 60 and a standard deviation of 10. A score has a z-value of –1.5. This is the raw score for that value.
What is 45?
When calculating sample variance, this value is used in the denominator to correct for underestimation.
What is degrees of freedom (n – 1)?