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