Stats
What is the frequency distribution? A count of how many scores take on each possible value for a variable
In what 2 situations would you use a grouped frequency distribution? When you have too many possible values and/or when several values yield counts of 0
What type of data is this: Data that measures categories. Not numbers. No ranking. Nominal data
What type of data uses rank? Ordinal data
What are continuous variables? Variables that can take on an infinite range of values
What are discrete variables? Variables that take on a limited number of values
Which type of variable is this: a special kind of discrete variable that only has 2 possible values. Dichotomous variables
What 2 types of data are bar graphs used for? Nominal and ordinal
What 2 types of data are histograms used for? Equal interval and ratio
What type of graph is this: bars don’t touch, x-axis is categories and data. Bar Graphs
What type of graph is this: bars do touch, x-axis is range of numbers. Histogram
Which type of data has true zero? Ratio
Which type of data is this: distance between each data point is equal but there is no true zero. Equal Interval
Which type of data is this: data represents categories and data is not naturally ordered. Nominal
Which type of data is this: data is naturally ordered but the difference between categories is not equal. (ie: a race). Ordinal
True or false: we can represent ANY of the scales of measurement with a number, but that doesn’t mean it has the same properties as a number (ex: postal codes). True.
Which type of data is the mode the most useful for? Nominal
Which 2 types of data can median used for? Ordinal and interval
What type of data is mean used for? Interval
Which measure of central tendency measures the most frequent values? Mode
Which measure of central tendency measures the middle score in a set of data? Median
Which measure of central tendency measures the average of a data set? Mean
When the mean is larger than the median, then the distribution will be skewed in what way? Positively skewed
When the mean is smaller than the median, then the distribution will be skewed in what way? Negatively skewed
Which measure of central tendency is strongly affected by extreme scores/values? Mean
Which aspect of measures of central tendency provide info about how spread out a frequency distribution is? Measures of dispersion
True or false: range is the simplest measure of dispersion and it provides a clear indication of the extreme values in a frequency distribution. True
True or false: Standard deviation is the least common measure of dispersion. False- it is the most common measure of dispersion.
What is variance? The average of the squared deviations from the mean
True or false: there can be more than one mode. True
Why wouldn’t you use the median for ordinal data? Ranked data already has a middle
How do you find the median if the number is odd? 1. Order data. 2. Add 1 to the # of observations/values and divide by 2. Whatever that number is, find that number in the set. (If you get 6, find the 6th value). If you get a half number or a number and a half, you circle the two numbers in between the values and add them together and divide by 2. That’s your median.
How do you find the median if the number is even? Divide by 2 and whatever that number is, find that number in the set. (if you get 6, find the 6th value)
What does it mean when the mean and the median are the same? It means there’s no skew. It's symmetrical.
True or false: the mean will always be the same or at least similar to the median when a data set is symmetrical/has no skew. True
How do you find variance? 1. Find the mean. 2. Subtract mean from all data points. 3. Square all responses. 4. Add all data points up. 5. Divide the answer by the number of values
What is variance? Variance is a statistical measurement of how spread out a set of numbers is. For a population, variance is the average of the squared deviation from the mean.
What are ordinal variables? Variables measures with a valuable property of measurement.
What are nonparametric analyses? a statistical method that makes few assumptions about the distribution of data.
What are nonparametric analyses used? It's often used when data is not normally distributed, or when a parametric test's assumptions are violated.
What are non-manipulated independent variables? a variable in a research study that the researcher measures but cannot actively change or control, typically consisting of participant characteristics like gender, age, or personality traits.
What goes on the x and y axis on a histogram? X-axis: possible values for our variable. Y-axis: frequency/count for each of those variables/values.