When you run a job with the FREQUENCIES command, you get back something called a
. This is simply a table that
If you find codes in the frequency table that are not supposed to occur in the data, you need to go back and correct or at least check them.
Sometimes you want to compute percentages using only cases with real responses. For example, suppose you have asked 100 people whether life is exciting or routine, and 25 said that it is exciting, 25 said that it is routine, and 50 told you to bug off. It would be a bit misleading, though it is correct, to state that 25% of those people think that life is exciting. A naive reader or listener would probably assume that the other 75% of the people find life unexciting. That is not really true, since the remaining 75% include people who declined to answer as well as those who find life routine. You can describe the results better by saying that half of the people who
Usually the frequency command has a column, labeled CUM PERCENT, which is also
When you execute this command, the computer produces a type of display that is called a bar chart because each line in the frequency table is turned into a bar. The length of the bar depends on the number of cases. (The actual frequency is given beside the bar.) At a glance, you can tell how often each of the responses was selected. You can also see whether one of the responses was an overwhelming favorite, and which responses are about equally likely.
Since computer screens and printers have a limited ability to show detail, responses that have similar frequencies may end up with bars of equal length even though the actual frequency counts are slightly different. This does not really matter. The point of a bar chart is to provide a visual summary of the data, and such minor distortions do not change the overall
Yet another statistic presented as an output of the frequency command is the CUM PERCENT. The cumulative percentage for a response is the sum of the valid percentages for that response plus all responses that precede it in a frequency table.
Depending upon the type of variable that you have used, the
If you think about the numbers used to code some of
Sometimes the order of categories is significant. Think about the exciting-routine-dull variable. The responses to the question can be arranged in a meaningful order. If we arrange them in terms of
Although the codes assigned to the exciting-routine-dull variable are ordered from high to low, they
On the other hand, let us say that "education" is one of the variables under study. This variable is different. The numerical code assigned to each category is not merely a code. It is the highest grade completed. It is an actual number, and we can treat it as such. For example, someone with 8 years of education has twice the number of years of education as someone with 4 years. Someone with 16 years of education has 4 more years than someone with 12