I’m manuevering around SPSS without the help of the manual, and I’m at a loss to tease out the results that I want. Help me, I beg you.
I need to be able to analyze three variables (two IV and one DV) to find quartile information. (We’re trying to create charts for our customers, so that they can compare their monthly usage of our products to the usage generated by other companies of their size. Since usage is not normally distributed, we want the charts to show the 5-point spread (min, Q1, med, Q3, max), rather than the mean.)
Let me explain what I’m doing:
I have customers grouped by size of corporation – 9 sizes in total (variable = SIZE). I have the number of searches each customer performed on our product (variable = SEARCHES), per month (variable = MONTH), for 3 years (variable = YEAR).
I compared means (going to “analyze” in the top menu, then “compare means,” then “means…”) using SIZE as the independent variable and SEARCHES as the dependent variable in the first level, then MONTH as the IV and SEARCHES as the DV on the second level. This gave me a really nice chart that showed me the average number of searches per month for each size category.
(I hope I’m explaining this clearly. In my chart, for example, the first chunk shows data for companies with 5-50 employees, and you see a row for each of the twelve months with the mean searches for that month. Then the next chunk on the chart shows the mean searches for each month for companies with 51-100 employees. Etc.)
Now this is really nice, but what I need is to be able to find quartile information for each category (25th, 50th, and 75th percentiles). But how?
I can look at more than two variables at once hen I find the descriptive statistics, but I can’t seem to tell the program that I want to find the median and quartiles SEARCHES for each MONTH for each SIZE. The size categories must be kept separate.
Does this make sense? Can you help? Please oh please?