I have collected a value of incoming 'results' every day over a period of 4 months. I want to check if the amount of 'results' coming in every day becomes less over time. This works well with a normal regression but in three of my datasets the 'amount of results' is not normally distributed. When i Perform a poisson log regression my parameter estimates table looks weird. It has a parameter value for every day. (one sample K-S test is non significant so the data is poisson distributed)
Could you guys help me find out what i do wrong? i have the feeling its due to the fact that the date is not categorical?
SPSS code:
DATASET ACTIVATE DataSet4.
* Generalized Linear Models.
GENLIN AANTAL_RES BY DATE (ORDER=ASCENDING)
/MODEL DATE INTERCEPT=YES
DISTRIBUTION=POISSON LINK=LOG
/CRITERIA METHOD=FISHER(1) SCALE=1 COVB=MODEL MAXITERATIONS=100 MAXSTEPHALVING=5
PCONVERGE=1E-006(ABSOLUTE) SINGULAR=1E-012 ANALYSISTYPE=3(WALD) CILEVEL=95 CITYPE=WALD
LIKELIHOOD=FULL
/MISSING CLASSMISSING=EXCLUDE
/PRINT CPS DESCRIPTIVES MODELINFO FIT SUMMARY SOLUTION (EXPONENTIATED).
