Quantitative Research

Descriptive Research Also called “Survey Research” Describes the way things exist Data collected Test hypothesis Or to classify opinions on issues/topics

Descriptive Research Most common research Surveys conducted Many fields covered: education, politics, social and economic More complicated than one may think

Descriptive Research Classified by data collection method Self report (survey) Observation (participants watched)

Descriptive Research Survey types Cross-sectional Longitudinal Data collected at one point in time Longitudinal More than once to measure growth or change

Descriptive Research Cross-sectional survey Single point in time may not provide perspective needed Example: census survey

Descriptive Research Longitudinal survey Collected multiple times from different samples and groups Four types of longitudinal surveys Trend, cohort, panel, and follow-up

Descriptive Research Trend survey Cohort survey How are attitudes changing or consistent among changing sample groups Cohort survey Different samples from the same group are surveyed over several time periods

Descriptive Research Panel survey Follow-up survey Same group and sample are surveyed over time Follow-up survey Similar to panel study, but performed after the panel study complete (examines later changes) Usually to evaluate a college instructional program

Descriptive Research Conducting self-report research Standardized, quantifiable information collected Questionnaire is written Interview is an in-person Q&A session between researcher and participant

Descriptive Research Conducting a Questionnaire study Most efficient Larger data sample collected Mailing is preferred

Descriptive Research Topic under investigation must be significant for subjects to respond Problem defined in specific objectives Each item on survey must directly relate to objectives

Descriptive Research Participants Chosen from appropriate sample Possess needed information and are willing to share it

Descriptive Research Questionnaire Brief, easily answered Structured (close-ended) response choices Facilitate easy responses Data analysis objective and efficient

Descriptive Research Questionnaire Structured items are scaled (ex. Likert) Unstructured items – complete freedom of response Provide more depth Difficult to measure

Descriptive Research Questionnaire Item construction Each questions focuses on one concept Concisely worded Concepts or terms with multiple connotations are defined Avoid leading questions

Descriptive Research Questionnaire Pretesting Smaller, but similar group Data will indicate any measurement difficulties and suggest improvement Make sure it measures what it is designed to measure

Descriptive Research Questionnaire Analyzing results Indicate % of respondents who selected each alternative answer for each item When possible, also analyze summed item clusters Groups of items focusing on same issue Variable relationships can be investigated (female vs. male responses) for each cluster

Descriptive Research Interview Study More in-depth data collected if successful More expensive and time-consuming Smaller sample population used

Descriptive Research Interview Study Written guide for administrator Includes any prompts or additionally allowed probing Standardized, comparable data requires all interviews must be conducted in same manner

Descriptive Research Interview Study Uses same guidelines from questionnaire construct Responses recorded manually or by recording device (participants must consent)

Correlational Research Data collected to determine: Is there a relationship between two variables? To what degree is the relationship? Degree of relationship is expressed as a correlation coefficient

Correlational Research Correlation coefficient Measured on a scale from +1.00 to -1.00 If variables highly related, correlation coefficient near +1.00 or -1.00 will be obtained If not related, a correlation coefficient near .00 will be obtained

Correlational Research Correlation coefficient Interpretation Lower than (+ or - ) .35 – low or none Between (+ or -) .35 and .65 – moderate Higher than (+ or -) .65 – High relationship

Correlational Research Correlation coefficient Interpretation A high relationship between two variables doesn’t necessarily mean one causes the other There may be a third variable that causes them both

Causal-Comparative Research Determines cause for differences in behavior or status of groups of individuals The effect and the cause have already happened Mostly studied in retrospect Example: Pre-school and social adjustment in 1st grade

Causal-Comparative Research Prospective approach slightly different Start with a cause and investigate its effect on a variable Example: social promotion in 7th grade

Causal-Comparative Research The independent variable A behavior or characteristic believed to influence some other behavior or characteristic (pre-school attendance) The dependent variable The change or difference in a behavior or characteristic due to an independent variable (social adjustment in 1st grade)

Causal-Comparative Research The independent variable Not manipulated in Causal-Comparative Research This is the major difference between this and Experimental Research In Causal-Comparative Research, groups are already formed and divided by the independent variable

Causal-Comparative Research The independent variable Basic Causal-Comparative Research design finds two groups differing on some independent variable, and comparing them on a dependent variable

Causal-Comparative Research Groups may differ in characteristics Select samples that represent their respective populations

Causal-Comparative Research Data analysis and interpretation Descriptive statistics The mean – average performance of group on a measure of some variable Standard deviation – measure the “spread” of scores around the mean (are they relatively close together or widely spread)

Causal-Comparative Research Data analysis and interpretation Inferential statistics t test – indicates if there is a significant difference between the means of two groups Analysis of variance – significant differences between means of three or more groups Chi square – does an event occur more frequently in one group than another?

Causal-Comparative Research Data analysis and interpretation Use caution Alleged cause-effect relationship may be the effect or a third factor may cause the independent and dependent variables Correct order of causality – which variable caused which? The one that occurred first

Experimental Research Researcher manipulates at least one independent variable Controls other variables Observes effect on one more dependent variables

Experimental Research Independent variable a.k.a. experimental variable, cause, or treatment Believed to make a difference in some performance

Experimental Research Dependent variable a.k.a. criterion variable, effect, or posttest Outcome of the study Measure of change or difference resulting from independent variable manipulation

Experimental Research Experimental studies yield the soundest evidence when conducted well Prove or disprove hypothetical cause and effect relationships

Experimental Research The process Select/define problem Guided by one hypothesis Researcher in control Experimental group receives unique treatment Control group receives different treatment

Experimental Research The process All other variables are equal to both groups that may effect dependent variable After exposed to treatment for some time, researcher applies dependent variable and measures differences

Experimental Research Manipulation and control Sets experimental apart from all others Three forms of independent variable manipulation Presence versus absence (A vs. no A) Presence varying degrees (much A vs. little A) Presence of one kind/another kind (A vs. B)

Experimental Research Manipulation and control Control: efforts to remove outside influences of any variable (other than independent variable) that may affect dependent variable

Experimental Research Two controlled variables Participant variables Members of different groups may have characteristic differences Environmental variables Any change in experimental setting that may influence performance differences

Single-Subject Experimental Research Studies individual behavior change Result of some treatment form Repeated formula Receives no treatment or intervention Tested Receives treatment / intervention