• Anchorage Community Survey 2007 Survey Sampling Design: Power and Sample Size

      ; Evans, Shel Llee (University of Alaska Anchorage Justice Center, 2006-12)
      This working paper documents the power analysis, literature review, and precision considerations contemplated in designing the Anchorage Community Survey’s (ACS) 2007 sampling design. The ACS will obtain at least 30 completed surveys from individuals in each of the 55 census tracts that make up the Anchorage Municipality, allowing us to discern a fairly small effect size of 0.30 with our smallest anticipated intraclass correlation and a moderate effect size of 0.40 with our largest anticipated intraclass correlation, both at 0.80 power level. This cluster sample size and number of clusters should yield sufficient precision to allow good estimation of variance components and standard errors, acceptable reliability estimates, and reasonable aggregated measures of constructed neighborhood variables from individual survey item responses.
    • Collective Efficacy and Firearms Violence in Anchorage, Alaska: Preliminary Findings

      Evans, Shel Llee; Langworthy, Robert H. (Justice Center, University of Alaska Anchorage, 2007-02)
      This paper seeks to advance the discussion of the utility of collective efficacy, as captured by Sampson, Raudenbush and Earls, in understanding community levels of crime by exploring the relation between community structure, collective efficacy, and in this case firearms violence, in Anchorage, Alaska. The specific aims of this paper are to report the results of a test of the collective efficacy thesis, modeled loosely after the test presented in the 1997 Science paper by Sampson, Raudenbush and Earls, as an explanation of neighborhood rates of firearms violence in Anchorage.