Ema
02-07-2006, 03:35 AM
Hi,
I am working in a project using data gathered for business purposes and I have a problem related to the observations in my samples.
A company distributed questionnaires to its employees, and then aggregated the results at unit level. So my sample consists of unit level data. I have data for 5 years. I cannot get any information regarding the individual answers. I would like to test whether there are differences between the departments, with respect to some issues discussed in the questionnaires. Moreover, I would like to see how the opinion with respect to those issues evolved during the years.
So far so good. It would seem I have repeated observations.
But there is a problem: the organizational structure changed every year (so departments were combined, new ones created etc), therefore the data for the same department (for 2 consecutive years) might not include the answers of the same employees (especially because filling in the questionnaire was not mandatory). Moreover, there is a different number of units every year, so my samples don’t have the same number of observations from year to year. So the observations are not precisely repeated observations.
How should I consider the observations? Repeated or independent? Are there any statistical methods which are not dependent of the type of observations?
Thank you in advance for your help.
BR,
Ema
I am working in a project using data gathered for business purposes and I have a problem related to the observations in my samples.
A company distributed questionnaires to its employees, and then aggregated the results at unit level. So my sample consists of unit level data. I have data for 5 years. I cannot get any information regarding the individual answers. I would like to test whether there are differences between the departments, with respect to some issues discussed in the questionnaires. Moreover, I would like to see how the opinion with respect to those issues evolved during the years.
So far so good. It would seem I have repeated observations.
But there is a problem: the organizational structure changed every year (so departments were combined, new ones created etc), therefore the data for the same department (for 2 consecutive years) might not include the answers of the same employees (especially because filling in the questionnaire was not mandatory). Moreover, there is a different number of units every year, so my samples don’t have the same number of observations from year to year. So the observations are not precisely repeated observations.
How should I consider the observations? Repeated or independent? Are there any statistical methods which are not dependent of the type of observations?
Thank you in advance for your help.
BR,
Ema