M346 exam 1
Ordinal
labeling+ order
Nominal
labeling, partition data into categories
Median
midpoint of all observed values
P-value
probability of observing a sample such as yours, if the null hypothesis was true. -Smaller the p-value, stronger the evidence to reject the null
Mean
the average of all observes values
Sample
A subset of the population
Census
Data about every member fro the population
How to use dummy coding
For M categories, we need to create M-1 dummy variables
Interval
Labeling+order+equal intervals between points
Ratio
Labeling+order+equal intervals between points+ meaningful zero point
When to use dummy coding
Nominal (categorical) variables with one possible answer
Why do we use Dummy coding
Only way to use nominal (categorical) variables in regression analyses
Sampling error
Random -The different between the sample result and the population result of a census collected with identical procedures. -statistical fluctuation that occurs due to chance variations
Standard deviation
Square root of variance
Sampling bias
Systematic problems due to sampling selection, sampling frame determination or non-response.
Sampling
The process of obtaining from a subset of a larger group
Dummy coding
assigning numbers to code data
Variance
average of the squared differences of all observed values from mean
measures of central tendency
mean, median, mode
4 measurement scales
nominal, ordinal, interval, ratio
measures of dispersion
range, variance, standard deviation
Null Hypothesis
refers to cases such as something is not present, there is no effect, no impact, no relationship, or there is no difference between different groups
alternative hypothesis
refers to what you think, what you believe, what your intuition tells you, the hunch that you have.
Range
the distance between the smallest and largest observes values
How to code a response depends on whether...?
the question is open or close ended
Cross tabs
the tables to see the relationships between two nominal (categorical) variables -IV goes in rows -DV goes in column -descriptive statistics-->cross tabs
Population
the total group of people from whom we need to obtain information
Mode
the value that is observed most frequently
