CCJ 4700 Exam 2 Stewart Updated 2024/2025 Verified 100%

Quota - Researchers try to make sure that the sample has the desired proportion of age, sex, etc. (The researchers use judgement rather than probability when selecting samples) What are the types of non-probability sampling? - -Purposive -Quota -Convenience -Snowball Threats to internal validity: - -History(past events may confound results) -Testing(Retesting influences peoples behavior) -Selection Bias(volunteers may choose to participate in certain study) What are the 3 components of a classical experiment? - 1)Pre & Post-Testing 2)Experimental & Control groups 3)Random Assignment ____________ Assignment Is a central feature of the classical experiment - Random Assignment Random assignment... - Reduces sources of bias & Creates equivalent groups Criteria for causality: - 1)Cause must come before effect 2)We have to show cause(x) came before effect(y) 3)We have to rule out rival explanations Why do we use sampling? - Bc... Its often not possible to collect info from all persons we wish to study & Its often not necessaryTwo things to do when selecting samples: - Select samples to represent a larger pop. of people/things & generalize from a sample to an unobserved population the sample is intended to represent When is a sample "representative" of the population? - When the aggregate characteristics of the sample closely approx. those same characteristics in the population 2 adv. of population samples: - -Typically more representative than other types of samples because they avoid biases -Permits us to estimate the accuracy of the sample Why is standard error important? - Bc it indicates how closely the sample estimates will be distributed around the population parameter As sample size increase ---> Standard error _______ - Decreases If sample size is quadrupled then standard error is: - Reduced by 1/2 What is the sampling Frame? - List of the population that one is interested in studying What are the types of probability samples? - -SRS -Systematic -Stratified -Cluster SRS - Number is assigned to each member in the frame and then a random number generator selects elements Systematic - You randomly select every nth number on a list(researchers use this when a list is available) Stratified (Proportionate) - First divide the population into strata and then choose your sample Stratified (Disproportionate) - You over sample certain groups When is Cluster sampling used? - Used when its impractical to create a list of the target population Purposive - Chose a sample based on the judgement and the "purpose" of the study Convenience - Researchers rely on availability Snowball - Get one subject who identifies with other potential subjects and so on Surveys may be used for: - Descriptive, explanatory, exploratory, and applied research What topics are appropriate for survey research? - -Counting Crime -Self Reports -Perceptions & Attitudes -Targeted victim surveys What makes survey research so challenging? - -Sensitive Questions -Rare Elements What are the guidelines for asking survey questions? - -Have a clear research problem -Create a variables list-Make items clear -Ask Short Questions Types of survey questions to avoid: - -Q's w/Bias -Double-barreled Q's -Vague Q's -Questions that require background knowledge -Objectionable Q's What are some advantages of open-ended questions? - -Greater detail in answers -Better when the researchers does know appropriate response categories -Dont bias respondent into selecting researchers choice