criminology -2025-08-19T14:40 .:33.740Z

  • Methods of scientific research (three main categories)

    • Quantitative research

    • Focus: numbers, data, and measurement

    • Characteristic: objective; “the numbers are the numbers” with little gray area

    • Uses: statistical analysis, testing hypotheses, large sample sizes

    • Qualitative research

    • Focus: text, language, and observations

    • Characteristic: more subjective; interpretive analysis

    • Uses: interviews, focus groups, text analysis, case studies, literature reviews

    • Process: interview participants with the same or similar questions, transcribe into written form, extract themes and word patterns to build a word map and draw conclusions

    • Mixed methods research

    • Combines quantitative and qualitative in one study

    • Rare due to the workload and complexity; involves collecting and integrating both data types

  • How these methods relate to research practice

    • All research starts with one of these three approaches

    • Choice depends on goals: measurement and testing (quantitative), understanding and exploration (qualitative), or both (mixed)

  • Quick comparison (video summary)

    • Quantitative:

    • Test hypotheses; data in numbers and graphs; requires larger samples

    • Data analyzed via math/statistics

    • Qualitative:

    • Formulate hypotheses; data in words; smaller samples

    • Data analyzed by summarizing, categorizing, and interpreting

    • Mixed methods:

    • Use both approaches in one study; increases methodological rigor but is resource-intensive

    • Example: student satisfaction in a university

    • Quantitative: survey 300 students; scale 1–5; result e.g., average score (e.g., 4.4/5)

    • Qualitative: interviews with 15 students; open-ended questions; identify recurring themes (e.g., need for more one-on-one guidance)

    • Mixed: start with interviews to generate hypotheses, then test with a larger survey; or start with a survey and follow up with interviews to understand reasons

  • Data collection for the three approaches

    • Quantitative data collection methods

    • Online surveys, in-person surveys, phone surveys

    • Experiments

    • Observations (quantified)

    • Qualitative data collection methods

    • Interviews, focus groups, case studies, literature reviews

    • Mixed methods sequencing

    • Start with qualitative interviews to gain insights, then test with a quantitative survey (larger sample)

    • Or start with a survey to capture the larger picture, then use interviews to understand the reasons behind results

  • Transition to criminology data sources (three primary sources)

    • Criminology relies on multiple data streams, commonly from government agencies and research surveys

    • Three primary sources (core focus of the lecture):

    • Uniform Crime Reports (UCR) / National Incident-Based Reporting System (NIBRS)

    • National Crime Victimization Survey (NCVS)

    • Self-report surveys (often by academics)

    • Ethical issues and data provenance matter when interpreting these sources

  • Deep dive: UCR/NIBRS (Uniform Crime Reports → National Incident-Based Reporting System)

    • What is UCR/NIBRS?

    • The UCR program is the long-standing, well-known crime data source collected from police reports across the U.S.

    • It has evolved into NIBRS, a more detailed, incident-based system that traces crimes more comprehensively.

    • How data are collected and reported

    • Data come from over 17,000 police agencies across the United States; not every agency reports every month

    • Data flow: local agency collects reports → state agency aggregates (e.g., SLED in SC, Alabama SBI) → FBI collects and compiles into national datasets

    • Reports are vetted before submission to FBI; the FBI then publishes national data via the Crime Data Explorer (CDE)

    • Part I (index) crimes vs Part II crimes

    • Part I crimes (index crimes) are historically the focus; eight categories total:

      • Violent crimes: Homicide, Rape, Robbery, Aggravated Assault

      • Property crimes: Burglary, Larceny, Motor Vehicle Theft, Arson

    • 1979 addition: Arson added to the index list

    • Part II crimes: crimes other than index crimes plus minor traffic offenses

    • Key properties and limitations

    • Strengths:

      • Large-scale, nationwide baseline based on police reports

      • Good for trend analysis of reported crimes, arrest data, demographics at arrest

      • Data are collected monthly and updated (vetting and standardization occur up the chain)

    • Limitations and common critiques:

      • Underreporting: not all crimes are reported to the police; common in many crime categories (the “dark figure of crime”)

      • Reporting practices: differences in local reporting, charging, and coding practices can distort national totals

      • Definitions and coding differences: state laws and FBI/NIBRS definitions don’t always align; e.g., a crime may be coded differently in different jurisdictions

      • Not a complete picture: not all agencies participate in NIBRS; federal offenses are not counted in NIBRS data

      • Misclassification: e.g., a simple burglary vs trespassing vs vandalism can be coded differently depending on jurisdiction

      • Apparent reliability vs reality: a high “clearance rate” can be misinterpreted if the denominator (reported incidents) is biased

    • The shift from UCR to NIBRS

    • 1982: UCR redesign began due to holes in the old system; aim to provide more detail and accuracy

    • Old UCR: if an incident involved multiple crimes, only the highest offense might be counted (hierarchical reporting)

    • NIBRS: counts all crimes within an incident (e.g., if a fight included vandalism and assault, both are reported)

    • NIBRS collects incident-level data: location, victim and offender data, relationships, weapons, drugs/alcohol involvement, etc.

    • 46 offenses in NIBRS (including the eight index crimes and many additional categories) and 46+ offenses broken down with subcategories

    • 1982–2021: gradual adoption; by 2021 (01/01/2021) NIBRS became the standard

    • Coding, offenses, and examples

    • Codes exist for each offense (example codes):

      • 13a: Aggravated Assault

      • 13b: Simple Assault

      • 13c: Intimidation

    • Robbery reclassification: now considered a crime against property rather than a personal offense in certain classifications

    • NIBRS adds many minor offenses and more detailed classifications (e.g., breaking down “Burglary” into specific categories like breaking into a building vs. a vehicle, etc.)

    • Data accessibility and use in coursework

    • The Crime Data Explorer (CDE) is the public interface to view NIBRS data and analyze trends by month, location, victim/offender demographics, etc.

    • You can customize views by month and offense, and extract data for analysis

    • Instructors often require students to pull data from CDE to compute totals over a period and to report per 100,000 people when comparing rates across years

    • Example usage (CDE snapshot in class demonstration)

    • Viewing homicides in a given month (e.g., February 2022): total homicides, percentage of population coverage, and the monthly or annual clearance rate

    • With CDE, you can see: location type (where it happened), victim-offender relationship, offender age, victim age, sex, race/ethnicity, etc.

    • Common finding: most homicides occur in residences (including homes) and relationships often unknown; many cases have unknown relationships due to ongoing investigations

    • Weapon type distributions commonly show handguns as the leading weapon in homicides and aggravated assaults

  • Crime Data Explorer (CDE) specifics

    • CDE provides a public interface to national and state data; you can select a crime (e.g., Homicide) and a time window to view monthly counts and related demographics

    • Key metrics shown in CDE visuals

    • Monthly counts of crimes reported to police (blue line in the demo)

    • Population coverage (top line; essentially the percentage of the population included in the data)

    • Clearance rate (gray line; cases with an arrest and charge or exceptional means)

    • Important caveats when using CDE

    • The national totals may require summing month-by-month data to get a period total since the public interface emphasizes per-month views

    • Population coverage is not the same as sample size; it indicates geographic and agency coverage

    • Clearance rates are influenced by multiple factors (arrests, extradition, jurisdictional issues, deaths, etc.)

    • Practical tips for students

    • When writing papers, compute total offenses over the specified years by adding monthly counts

    • Use per 100,000 population rates to compare across years or jurisdictions

    • Include location and demographic breakdowns (e.g., victim-offender relationship, age, sex, race) to add depth to analysis

  • National Crime Victimization Survey (NCVS)

    • Purpose and design

    • Created by the Bureau of Justice Statistics (BJS) in 1973 to estimate the “dark figure” of crime—the crimes not reported to police

    • It is a victim-focused survey, meaning it asks respondents about their victimization experiences

    • It captures information not typically present in police reports, including the frequency and consequences of crimes

    • Sample and methodology

    • Approximately 95,000 households in a three-year panel; ages 12 and up in those households are eligible

    • The panel is followed for seven interviews over three years (an intake followed by six follow-ups)

    • Data collection has evolved from mail surveys to computer-assisted, web-enabled or interview-based approaches

    • What NCVS collects

    • Victim demographics: age, race, gender, income, education

    • Crime characteristics: type of crime, time, location, weapons used, injury, economic impact (e.g., job loss, hospitalization)

    • Experiences with the criminal justice system and the victim’s perception of justice response

    • Information on whether victims used protective measures

    • Coverage and limitations

    • Not all crimes are surveyed; notably, homicide is excluded by design because you cannot interview a deceased person

    • Advantages: provides a broader view of crime beyond police reports, helps quantify the dark figure of crime, reveals victim experiences and economic impact

    • Limitations: relies on self-report; potential misreporting or misinterpretation by respondents; memory biases; some crimes may be misclassified; memory decay over time; respondents may fear repercussions or fail to report certain details

    • Examples and insights from NCVS comparisons

    • Rape/Sexual assault: historically a high rate of underreporting in police data; NCVS often reveals higher victimization levels than police reports alone

    • In 2012, NCVS figures for rape suggested substantially higher victimization than UCR police counts (rape is one of the most underreported crimes in police data; NCVS helps illustrate the true scale)

    • Limitations and interpretation cautions

    • The NCVS cannot measure homicide (deceased victims cannot be surveyed)

    • Self-reported data require careful interpretation due to potential misclassification and recall biases

    • Self-report surveys (academic research surveys)

    • What they are

    • Surveys designed and conducted by university researchers