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SW R & STATS Midterm
Hypothesis | proposes a relationship between 2 or more variables. One variable influences another variable. |
Independent Variable | the variable that causes or leads to another variable. |
Dependent Variable | this variable varies depending on the other variable. |
Concept | is a mental image that summarizes a set of similar observations, feelings, or ideas. |
Conceptualization | is the process of specifying what we mean by a term. |
Operationalization | is the process of connecting concepts to observations. When we identify specific observations that we will take to indicate that concept in empirical reality. |
Research Questions emerge from: | Own experiences, Research literature; Theories; Pragmatic(real world) |
We evaluate research on: | Feasibility; Social Importance; and Scientific relevance |
What is sampling? | -some part of a larger body specifically selected to represent the whole. It is taking any portion of a population or universe as representative of the population or universe. |
Sampling | The procedure by which a few subjects are chosen from the universe to be studied in such a way that the sample can be used to estimate the same characteristics in the total. |
Advantages of Sampling | Less costly, quicker and, if selected properly, gives results with known accuracy that can be calculated mathematically. |
Why use Sampling? | Impossible to observe all relevant events. Time Cost |
Population | The collection of all individuals, families, groups, organizations, and events that we are interested in finding out about. |
Target Population | Is the population to which the researcher would like to generalize his or her results. |
Survey Population | Operational definition of the target population; that is, a target population with explicit exclusions. |
Element/Unit of Analysis | The unit about which information is collected and that provides the basis of analysis. Each member of a population is an element. |
Sample Design | A set of rules or procedures that specify how a sample is to be selected. This can be either probability or nonprobability. |
Sample Size | The number of elements in the obtained sample. |
Sampling Error | The degree of error to be expected for a given sample design; the difference between the sample mean and the population mean. |
Sampling Bias | The notion that those selected are not "typical" or "representative" of the larger populations that have been chosen from. |
Confidence Level | -How often one could expect to find similar results if the survey were repeated. -The degree of certainty of obtaining the same results. -Often informs about how often the findings will fall outside the margin of error. |
Confidence Interval | The range in which we are fairly certain that the population value lies. |
Statistical Inference | The process of reasoning by which information about a population is extracted from a sample data. |
Probability Sampling | {known in advance] every person in the population has an equal chance of being selected. Each unit in the population has an equal chance of being selected. |
Non-Probability Sampling | we do not know [in advance] if every person in the population has an equal chance of being selected. Chance of being selected in unknown. |
Types of Probability Sampling | -Random Sampling -Systematic Sampling -Stratified Sampling -Cluster Sampling |
Random Sampling [Probability Sampling] | -selected by chance. -Must have equal access to everyone in the population at the same time. -Lottery |
Systematic Sampling [Probability Sampling] | -Choice of being selected in a sample in not random, but systematic choice. -Ex: First element is selected randomly then every "nth" participant is selected. |
Stratified Sampling | -stratifies the population into subgroups and then randomly selects from each subgroup. -All elements in the sampling frame are distinguished according to their value on some relevant characteristic. -that characteristic forms the sampling STRATA |
Cluster Sampling | -used when people in a population of interest cannot be identified in a direct way. -Less likely to be representative because more than one stage is needed to identify the sample. Each stage poses likelihood of error in selection. |
Types of Non-Probability Sampling | -Convenience Sampling -Quota Sampling -Criterion Sampling -Snowball Sampling |
Convenience Sampling [Non-Probability] | Selection of elements is done by what is available and/or convenient to the researcher. |
Quota Sampling [Non-Probability] | -intentionally compare 2 or more subgroups. -does not use random sampling -pre-set number of elements based on characteristics in a population to ensure that the sample represents those characteristics in the population. |
Criterion Sampling [Non-Probability] | -selects participants based on a set of criteria related to the purpose of the study. -AKA Purposive Sampling |
Snowball Sampling [Non-Probability] | -used when it is difficult to identify or locate the kinds of people who are the focus of the study. -select and interview people who fit criteria and then participants are asked to identify and recruit others. |
How to determine sample size: | -Type of analysis to be employed -The level of precision needed -Population homogeneity/heterogeneity -Available resources -sampling techniques used in research with population. |
Sample size in types of sampling: | Probability: samples are larger because they have different purposes. They need to mathematically account for or measure error. Non-Prob: is usually used in exploratory studies when we need to know more about the population. |
Non-Sampling Errors | -an inadequate sampling frame -nonresponse from participants -field errors -response errors coding and data entry errors |
Factors that affect choice of sample design: | -stage of research -data use -available resources for drawing sample -nature of the research design |
Quantitative Measures | When we have numbers we can analyze information using statistics. -Ex: height, weight, how many, pounds, test scores, income. |
Qualitative Measures | We can use open ended questions to get sentences, paragraphs etc. -Ex: gather words, gender, race, religion, satisfactions. -we gain flavor, attitudes, intentions from participants, but we have more difficulty using statistics. |
Levels of Measurement | -Nominal -Ordinal -Interval -Ratio |
Nominal | -With this measurement, you indentify variables whose values have no mathematical interpretation; they vary in kind or quality but not in amount. -Qualitative, no mathematical interpretation. |
Ordinal | With this measurement, you specify only the order of the cases in "greater than" and "less than" distinctions. |
Interval | With this measurement, numbers are represented in fixed measurement units but have no absolute zero point. |
Ratio | With this measurement, numbers are represented in fixed measuring units with an absolute zero point. -can be added and subtracted as well as multiplied and divided. |
How can we get data? | -Observations -Use existing data -Use surveys/questionnaires -Triangulation: combine measure-most useful |
Direct Observation | -Observing someone/thing directly |
Indirect Observations | -Unobtrusive measures: information is gathered without direct knowledge or participation. -Content Analysis: looks at representations of the topic in various media forms such as new reports, tv shows, magazines, etc. |
Existing Data | -Archived data set at the federal and state level or at the agency level. -Certain types of annual or less frequent reports, i.e, the census. |
Surveys/Questionnaires | -Self-report and administered -Standardized -Can test a variety of problems for many ages -Many surveys can be used that are already developed-convenient. |
Scales and Indexes | -A group of questions in which the total responses to the questions are summed or in some other way manipulated to provide a more complex or complete measure of a concept than can any single question or component element of the scale or index. |
Reliability | -is concerned with questions of stability and consistency. Does the same measurement tool yield stable and consistent results when repeated over time. -refers to a condition where a measurement process yields consistent scores over repeated measurements |
Validity | refers to the extent we are measuring what we hope to measure(and what we think we are measuring). |
Types of Reliability | -Test Retest -Inter-item -Interobserver |
Test-Retest Reliability | When the researcher administers the same measurement tool multiple times, asks the same question, follows the same research procedures, etc. -Does she obtain consistent results? -Simplest method for testing reliability. |
Inter-item Reliability | -this is a dimension that applies to cases where multiple items are used to measure a single concept. |
Interobserver | -is concerned to the extent to which different interviewers or observers use the same measure and get equivalent results. -if different observers or interviewers use the same instrument to score the same thing , their scores should match. |
Face Validity | this criterion is an assessment of whether a measure appears , on the face of it, to measure the concept it is intended to measure. -very minimal assessment. -if a measure cannot satisfy this criterion, then the other criteria are inconsequential. |
Types of Validity | -Face Validity -Content -Criterion-related -Construct |
Content Validity | -is concerned with the extent to which a measure adequately represents all facets of concept. |
Criterion-related Validity | -applies to instruments that have been developed for usefulness as indicator of specific trait or behavior, either now or in the future. -Ex: an individual's performance on a driving test correlates well with his/her driving ability. |
Construct Validity | -is concerned with the extent to which a measure is related to other measures as specified by theory or previous research. -is established if the measure covers the full range of a concepts meaning. |
Criterion Validity | -Predictive: which is the ability of one measure to predict the score on the criterion measure in the future. -Concurrent: when the core on the new measure resembles in some predefined fashion the scores on the criterion measure. |
Five Criteria for establishing a casual relationship: | -Empirical association -Temporal priority of the independent variable -Non-spuriousness -Identifying a causal mechanism -Specify the context in which the effect occurs |
Empirical Association | The independent variable and the dependent variable must vary together. -A change in X is ASSOCIATED with a change in Y. |
Temporal Priority of the Independent Variable | The change in X must occur before the change in Y. |
Non-spuriousness | We say that a relationship between two variables is spurious when it is due to variation in a third variable; so what appears to be a direct connection is in fact not. |
Casual Mechanism | Is the process that creates the connection between the variation in an independent variable and the variation in the dependent variable it is hypothesized to cause. |
Context in which the effect occurs | No cause has its effect apart from some larger context involving other variables. -When, for whom, and in what conditions does this affect occur? -a cause is really one among a set of interrelated factors required for the effect. |
Experimental Group | -is the group of subjects in an experiment that receives the treatment or experimental manipulation. |
Comparison Group | -is the group of subjects that is exposed to a different treatment than the experimental group(or that has a different value on the independent variable). |
Control Group | -is the group of subjects that receives no treatment instead of a different treatment. |
PreTest | is a measurement of the dependent variable prior to initiating the treatment(independent variable). |
Post Test | is a measurement of the dependent variable subsequent to the treatment(independent variable). |
Internal Validity | -whether the intervention rather than other factors is responsible for improvement. What other factors may be responsible for change? |
External Validity | -Can the results of this sample be generalized to the larger population? |
Research Design TYPES | -Pre-Experimental -Quasi-Experimental -True Experimental |
Pre-Experimental Design | 1.One-group Post test only design: an intervention followed by a measure, weakest, cross-sectional. 2.One-group Pretest/post test design: pretest, then intervention, then post test, a little stronger, longitudinal. |
Quasi-Experimental Design | 1. Pretest/Post test Comparison group design: has comparison group which does not receive intervention, longitudinal. 2. Time series design: multiple measures of the client outcome prior and after intervention, no comparison or control group, longitud. |
True Experimental Design | 1. Prestest/Post test Control group design: pretest/post test design that involves a control group, longitudinal. RANDOM. |
Two Ethical Issues | Deception:in general subjects must be informed as the the purpose of the study. Distribution of Benefits: to what degree are persons harmed who do not receive the benefit of the treatment or who received the treatment when compared to the other group. |
Independent Variable | -the variable that causes or leads to another variable. -in intervention research, this can be the treatment variable. |
Dependent Variable | -this variable varies depending on the other variable. -in the intervention research, this can be the outcome variable. |
Mode | -the value that occurs most often in a series of numbers. |
Median | -middle value when numbers are arranged in order. (better to use median than the mean when there are outliers) |
Mean | -Average: sum of all the numbers divided by the total numbers. |
Frequencies(measures) | -percentages help us visualize the data in charts and graphs. |
Valid Percent(measures) | -is the number of the item including the missing or other codes. |
Cumulative Percent(measures) | -is the number of ind's in that grouping and below. |
Varience | -average squared deviation of the mean. |
Standard Deviation | -the amount, on average, that scores or responses vary from the MEAN score. |
Inferential Statistics | -refers to the various tools that help us determine how much confidence we have when we generalize our findings from a sample to a population. -in this case, we always assume that there will be some "margin or error". |
Hypothesis Testing | Null Hypothesis: there is no relationship/association between variables. Alternative Hypothesis: there is a relationship between the variables. |
Errors | Type 1 Error: you reject the NULL and it is true. Type 2 Error: you accept the NULL and it is false. |
Statistical Significance | -relationship between two variables that is determined by math principles--based on a probability that making this claim, I will only be wrong less than .05 percent of the time. I am 95% confident that my answer is not due to error. |
Clinical Significance | -is determined by the judgement of professional--exploring the claim that a relationship exists between an intervention and a client outcome variable. -single subject designs help do this. |
Cross-Tabs Contingency Tables | -builds upon our understanding of the Bernoulli Process. -used for categorical data to examine if two variables are independent of each other or is there an association between them. -this independence may be tested using a chi-square statistic. |
Bivariate Tests | Chi-Square: determines whether 2 variables at the nominal or ordinal levels are statistically independent of each other. -used for categorical variables |
Student's t-test types | Independent Sample: this means from 2 different groups of people. Paired Sample: this means fro the same group of people measured twice. -SPSS has both commands for these. |
T-test's assume... | -outcome variable is normally distributed. -sample is randomly selected. -sample size may be small. |
Correlation Coefficient | -how 2 continuous variables may be related to each other. -tells the strength of a relationship between 2 variables and also its nature. -values from -1.0 to 1.0 |
Regression Analysis | -this technique is used to PREDICT the value of the dependant variable(outcome, y) from one or more independent variables(x) -this prediction is usually in the form of a linear equation. |
Multiple and Logistic Regression | Multiple Regression:allows you to use 2 or more independent variables to predict a continuous dependent or outcome variable. Logistic Regression: is used for predicting a dichotomous outcome variable. |
Research Questions | -questions about the social world that you seek to answer through the collection and analysis of firsthand, verifiable, empirical data. |
Research Foundations | -empirical or actual research studies -single case designs -Lit. Reviews -books and book reviews |
Theories | -help us make sense of social phenomena. -they are used to explain and predict behavior/attitudes etc. |
Scientific Method's findings should be.... | true, repeatable, generalizable, and it's knowledge is valid and reliable. |
Social Science Approach | -relies on logical and systematic methods to answer questions and its done so others can evaluate, dispute or replicate the findings. -asking questions, observing, counting, are all basic methods used. |
Types of Research | -Descriptive -Exploratory -Explanatory -Evaluation |
Descriptive Research | -defining and describing social phenomena, often first done on a new topic. |
Exploratory Research | -no explicit expectations, captures large amounts of unstructured info. |
Explanatory Research | -identifies cause and effect and to predict how one phenomenon will change or vary in response to another phenomenon. |
Evaluation Research | -determines the effects of a program or intervention. |
Quantitative methods | -surveys or experiments which produce numbers, percentages, counts. |
Qualitative methods | -interviews, focus groups, surveys which produce written or verbal comments or text. |
Triangulation | -use of multiple methods of Quantitative and Qualitative. |
Errors in Research | -Observing: selective observation and inaccurate observation. -Generalizing: over generalization -Reasoning: jumping to conclusions. -Reevaluating: resistance to change(reluctance to modify ideas in light of new info) |
Goal of Research | to figure out how or why the social world operates as it does. It is the goal of validity---truth. |
Research | -is defined as a systematic investigation, including research development, testing and evaluation, designed to develop or contribute to generalizable knowledge. |
Human Subject | -is defined as a living individual about whom an investigator conducting research obtains (1) data through intervention or interaction with the individual, or (2) identifiable private information. |
Ethical Problems in Research | -Physical Harm -Psychological Harm -Invasion of Privacy (without consent) -Deception -Misrepresentation of Findings -Balancing risks and gains |
Confidentiality | -the researcher knows the names of the participants but promises not to disclose those names to anyone outside of the team. Data cannot identify anyone. |
Anonymity | the researcher does not know the names of participants. |
Informed Consent | the researcher must give info to potential participant about the study and risks and benefits of it. Participant can stop at any time. |
Institutional Review Board | group at an institution who review potential studies and determine if they are ethically sound. Must approve before beginning. |