Lecture 2: Types of Studies, Target Populations, & Ethical Concerns CRIM 430 Lecture 2: Types of Studies, Target Populations, & Ethical Concerns

Types of Studies Once you have a research question, the next step is putting together an appropriate research design to answer your question One of the most important parts of this process is deciding what type of study you will conduct What type of time dimension does your study require—cross-sectional or longitudinal? The type of design you choose must “fit” with your research question

Cross-Sectional Studies Cross-sectional: Collection of data at one point in time Best for exploratory and descriptive studies Example: U.S. Census or a police survey to discover what the primary concern of citizens is Strengths Cost-efficient Fewer logistic problems Disadvantages Tries to understand causal processes based on observations observed at one point in time

Longitudinal Studies Longitudinal studies: Designed to allow observations over a period of time There are different types of longitudinal studies Trend, cohort, and panel studies Strengths Better for testing causal processes Allow for more in-depth understanding of behavior Weaknesses Expensive Logistically more complicated and time consuming Attrition (losing respondents)

Types of Longitudinal Studies Trend studies=examine changes within the general population population over time Example: UCR Cohort studies=examine more specific populations as they change over time Cohorts=a group of people who enter or leave an institution at the same time Example: Examining job placement success of CSLA graduates by the year they graduated Panel studies=same set of people are interviewed two or more times over time Example: NCVS

Comparison of Longitudinal Studies Research topic: Arrests for burglary A trend study=Examine shifts in burglary arrests during this time using the UCR A cohort study=Select a group of individuals because of age/entering or leaving institution at the same time & follow over time A panel study=Select a group of individuals and ask them questions 2+ times over time

Direction in Studies Retrospective research: Asks respondents to recall their past Potential problems: Poor memory Lying Unavailable or incomplete records Looking backward has limitations Prospective research: Begin with a sample and follow their behavior into the future Can be used within a cross-sectional framework Sample selection differs and plays a critical role in each approach

Approach Comparisons Prospective: What % of abuse victims later abuse their children? Time 1 Time 2 Parents Victims 206 Not Victims (81%) 1 Victim 49 Victims (19%) 9 Victims Retrospective: What % of abuse victims have parents who were abused? 1 Not Victims 10 Victims .5% 18% 10% 90%

Choosing a Study Type Does your research question imply time? Can you use a snapshot of data to answer your question or do you need to assess your question over a period of time? If time is implied in your research question, is it more appropriate to look backward or to look forward in time? Ultimate selection of a study type will be completed once your research design is selected (I.e., experimental or non-experimental)

Identifying a Target Population Another critical aspect to preparing your research methodology is deciding who your target population will be Target population=Who is the focus of your study? Selection criteria=the characteristics that define the boundaries of your target population Defining a target population is critical to selecting a sample

Relationship b/t Population & Sample Target Population Sample

Units of Analysis Target populations may be (what): Individuals-data are derived from individuals and used to describe the individuals Groups-data are grouped into categories and compared across those categories Organizations-data are grouped by organization and compared across those organizations Social Artifacts-products of social beings and their behavior are compared to identify patterns Mixture

Avoid Mistakes Ecological Fallacy: Applying results from group analysis to individuals Individualistic Fallacy: Applying information related to an individual to groups of individuals

Ethical Issues All research is bounded and defined by professional code of ethics Social science research is particularly subject to ethical codes because it almost always includes humans subjects When conducting research, it is necessary to balance the potential benefits from doing the research against the possibility of psychological, emotional, and physical harm

IRB All human subject research conducted at a University must be reviewed and approved by the Institutional Review Board The IRB ensures that federally defined safeguards are applied in all types of research with humans Code of Federal Regulations Title 45, Chapter 46, U.S. Department of Health & Human Services Additional rules apply to two populations considered particularly vulnerable: Prisoners Children

IRB Safeguards Safeguards include: Written consent form must be used to request participation in the study Written list of benefits and costs of participation Subject must voluntarily participate Subject must be guaranteed anonymity or confidentiality Analysis of data in the aggregate Protection from deceit by researchers