Types of Hypotheses in Guns & Crime Research Gun Ownership Crime Promote + Gun Ownership Crime Deter - Directional (alternative) Hypothesis 1.What would be the null hypothesis ? 2.What would be the bi-directional alternative hypothesis?
Variables in Guns & Crime Article How many people in the US own guns Passage of concealed firearms legislation “Handgun magazine” sales data of states & counties Number of gun shows Gun-related deaths Homicide rates Non-gun related homicide rates Burglary, Larceny rates Robbery, Assault, rape, car theft rates
Types of Variables in Guns & Crime Research How many people in the US own guns= Predictor/IV Passage of concealed firearms legislation = Predictor/IV “Handgun magazine” sales data of states & counties =Predictor/IV Number of gun shows=Predictor/IV Gun-related deaths=Criterion/DV Homicide rates=Criterion Non-gun related homicide rates=Control (or DV) Burglary, larceny=DV Robbery, assault, rape, car theft rates=Control (or DV)
Which design establishes the causal relationship with more certainty? Why? –Field Experiment Recall, experiments establish cause via Manipulation of cause (aka treatment) Temporal precedence of cause (and no other factor) before effect Control of all other extraneous factors Practice concepts learned with Guns & Crime Article
By Establishing cause via –Manipulation of cause (aka treatment) –Temporal precedence of cause (and no other factor) before effect –Control of all other extraneous factors How do experimental designs attain precision?
StudyType A Field Study B C D Field experiment
StudyType E Sample Survey/Meta-analysis F Field Study G H Laboratory Experiment
Identifying Variables Exercise (Handout behind Student Info Qs from last week) Study NamePredictor/IVDependent/Criterion Parenting StylesNeglectful vs. non neglectful parenting style Academic performance / achievement strategies Alcohol StudyAlcohol involvementEducational attainment Baby Study -- Lullabies sung vs. not sung to babies -- Gender of baby Days in hospital Television Study--Amount of TV watched --Gender of participant Perceptions of health
Study NameType of Study Parenting StylesField Study Alcohol StudyField Study Baby StudyField Study Television StudyField Study Identifying Variables Exercise (Handout behind Student Info Qs from last week)