TY  - JOUR
PY  - 2015//
TI  - What is the best way to analyze less frequent forms of violence? The case of sexual aggression
JO  - Psychology of violence
A1  - Swartout, Kevin M.
A1  - Thompson, Martie P.
A1  - Koss, Mary P.
A1  - Su, Nan
SP  - 305
EP  - 313
VL  - 5
IS  - 3
N2  - OBJECTIVE: Most frequency data on violence are non-normally distributed, which can lead to faulty conclusions when not modeled appropriately. And, we can't prevent what we can't accurately predict. We therefore review a series of methods specifically suited to analyze frequency data, with specific reference to the psychological study of sexual aggression. In the process, we demonstrate a model comparison exercise using sample data on college men's sexual aggression. <br><br>METHOD: We used a subset (n=645) of a larger longitudinal dataset to demonstrate fitting and comparison of six analytic methods: OLS regression, OLS regression with a square-root-transformed outcome, Poisson regression, negative binomial regression, zero-inflated Poisson regression, and zero-inflated negative binomial regression. Risk and protective factors measured at Time 1 predicted frequency of SA at Time 2 (8 months later) within each model. Models were compared on overall fit, parsimony, and interpretability based upon previous findings and substantive theory. <br><br>RESULTS: As we predicted, OLS regression assumptions were untenable. Of the count-based regression models, the negative binomial model fit the data best; it fit the data better than the Poisson and zero-inflated Poisson models, and it was more parsimonious than the zero-inflated negative binomial model without a significant degradation in model fit. <br><br>CONCLUSION: In addition to more accurately modeling violence frequency data, count-based models have clear interpretations that can be disseminated to a broad audience. We recommend analytic steps investigators can use when analyzing count outcomes as well as further avenues researchers can explore in working with non-normal data on violence.<p />  <p>Language: en</p>
LA  - en
SN  - 2152-0828
UR  - http://dx.doi.org/10.1037/a0038316
ID  - ref1
ER  -