THE BASICS
Identify the IV and DV in the following hypothesis:
H1: Education is positively associated with income.
IV = education
DV = income
‼️Remember: The IV causes a change in the DV‼️
What is the difference between a frequency polygon and a histogram?
In a histogram, the frequency is represented by bars rather than lines.
What is one measure of central tendency?
Mean, median, or mode.
What is one way to measure dispersion?
Range, variance, or standard deviation.
What is x-bar?
The mean
What is the difference between a population and a sample?
• A population is a comprehensive and well-defined group.
• A sample is a subset of a population we observe (used to make inferences about the population from which the sample was drawn).
What are two ways that the shape of a distribution can deviation from normality?
1.) Skewness
2.) Kurtosis
What is central tendency?
A statistical indicator of the center of a distribution.
What is dispersion?
The differences among scores in a distribution. It describes the degree to which scores are spread out or clustered together.
What is the equation for the mean?
The sum of the scores divided by the number of scores.
What is the difference between a discrete vs. a continuous variable?
• Discrete – nominal or ordinal
• Continuous – interval or ratio
What is kurtosis?
The extent to which a distribution is peaked or flat.
🔍 Distributions can be mesokurtic (normal), leptokurtic (peaked), or platykurtic (flat).
The mode is your only choice when you have _____ level measurement.
Nominal
Why isn’t the range an ideal measure of central tendency?
It only takes two values into account and it’s susceptible to extreme scores.
What is the equation for the standard deviation?
Square root of s-squared (i.e., variance)
What are the five phases in the research process?
1.) Conceptualization
2.) Operationalization
3.) Data collection
4.) Data analysis/interpretation
5.) Reconceptualization
What is skewness?
The extent to which a distribution has a peak on either side of the distribution.
What is the median?
The point in a distribution above which one-half of the scores fall and below which half of the scores fall.
What is the variance?
A measure of dispersion that works with squared deviations from the mean.
What is the equation for variance?
Sum of squares divided by (n - 1)
(draw on board)
List and give an example of the four levels of measurement.
1.) Nominal (favorite color)
2.) Ordinal (ranking of runners in a race)
3.) Interval (Likert scales)
4.) Ratio (height)
Draw a positively skewed distribution.
• Positive means the tail points right
• Negative means the tail points left.
What is the mean and why is it the preferred measure of central tendency?
The mean is the average.
‼️The mean takes:
• All scores into account
• The quantitative value of scores into account
What is n-1 in the denominator of the equation for the variance?
The degrees of freedom (i.e., the number of scores that are free to vary).
What is the equation for sum of squares?
(draw on board)