Benjamin Spivak
benspivak.bsky.social
Benjamin Spivak
@benspivak.bsky.social
Senior Lecturer, Centre for Forensic Behavioural Science, Swinburne University of Technology
I think predicting an offended yes/no would still require you to select a threshold (or cutoff) probability for when a case is considered as predicted to offend in the model? e.g. in cases where the log reg predicts a greater than 50% prob. of offending you are a yes otherwise no.
November 27, 2024 at 11:48 AM
Agree, but can be massively misleading for log reg in my experience because it depends on where you set the threshold for "correct" predictions.
November 27, 2024 at 11:36 AM
Yeah, I saw this. The brier score is about the closest to what I was after but not really that informative about the absolute predictive performance of the models (as opposed to performance relative to the other models).
November 27, 2024 at 11:30 AM
These do not need to be included in the statistical model but can be collected at the same time by officers.
November 27, 2024 at 11:25 AM
Agree on shorter being better from a model parsimony perspective BUT sometimes the presence of additional questions are viewed positively (provided that they are not asked in a robotic checklist type way) by affected family members and serve purposes other than prediction (e.g. risk management)
November 27, 2024 at 11:21 AM
Guessed this was based on using the AUC as a measure of predictive performance. The claim of superior performance is silly if you are not directly testing against these tools in the sample.

It would be interesting to see the ppv at different model thresholds.
November 27, 2024 at 8:37 AM
Excellent. Thanks. Followed.
November 25, 2024 at 11:13 AM
Thanks Manne. Very helpful. Had no idea about starter packs but I have followed everyone on Matt's.
November 25, 2024 at 10:11 AM
Oh agreed. I am really only familiar with you from your book, so I thought it strange that you would be seen as a puppetmaster type figure based on that. Sorry that you have to put up with such nonsense.
November 19, 2024 at 12:47 PM
Obviously the 10s of thousands of murders part is insane. But why are they referring to you as the architect behind "Soros DAs"? Is this all just in relation to your book and academic work?
November 19, 2024 at 8:20 AM
The proportion of "other" is interesting. I am guessing the share of Black recruits is same or higher than the share in the general population. I wonder whether recruits from other backgrounds are underrepresented and whether this is related to how policing is viewed as a career in thesr communities
November 15, 2024 at 12:11 AM