Introduction to Simple Univariate Descriptive Statistics
- Frequencies and Percentage Distributions
- Can be used for nominal and ordinal variables, interval usually when the data are collapsed.
- Difference between proportions (f/N) and percentages (f/N)* 100
- How to set up
- Put the values of the variable along the side, including totals, list frequencies or percentages in a second column
- But what if you have interval data?
- One way to group the data
- Subtract the lowest value from the highest value
- Divide the subtraction by 10, this will give you your approximate class interval (ie how large each group is)
- Round what you found in “b” so it is either an even number or a multiple of 5.
- Establish the smallest interval so it starts with a multiple of the number you calculated in “c”
- Group the data into these ranges
- One way to group the data
- And what do you do with missing values?
- If important, percentage them
- Otherwise list in the bottom of the table
- How to read
- It will depend on your question. Often you compare several percentage distributions to each other.
- Rates = the number of cases with the selected value/population size
SPSS: Introduction and constructing frequency distributions
Assignment
(All in Social Statistics for a Diverse Society)
Chapter 2 SPSS problem 2, and chapter exercises problem 4
Notice that each chapter has hand calculation exercises and SPSS exercises