Hi Rick. Thank you for your answer!
I am evaluating an intervention and looking to find out whether levels of incidents (e.g. verbal abuse, harassment, etc.) have reduced following the intervention. I recorded the number of incidents on a weekly basis for 6 months prior to and following the intervention.
So the DV is number of incidents and the IV is is the intervention. I have attached the output - as you will see, there is no predictor (i.e. intervention) in the model despite having included this in the analysis.
I have conducted the same analysis (step by step) with another DV (i.e. incidents of harassment) and the predictor (intervention) is retained in the model.
I am new to ITSA so I may be looking at this the wrong way!
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Carolina Antonini
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Original Message:
Sent: Mon October 18, 2021 02:36 PM
From: Rick Marcantonio
Subject: Interrupted Time Series Analysis
Hi, Carolina. Would it be possible for you to share either a sample or simulation of your data and the syntax you used? Thanks.
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Rick Marcantonio
Quality Assurance
IBM
Original Message:
Sent: Mon October 18, 2021 08:09 AM
From: Carolina Antonini
Subject: Interrupted Time Series Analysis
Hi all. I have conducted an Interrupted Time Series Analysis using the forecasting option/ARIMA model.
For some reason the predictor variable is being omitted from the model in the output. I am pretty sure I have done everything correctly although do not understand why this is happening and wondering if anyone could help? Does this mean the predictor does not fit the model? Any input is much welcomed!
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Carolina Antonini
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#SPSSStatistics