Conceptual variable
definition, uses words or concepts to define a variable. (Independent)
a label or name that represents a concept or characteristic that varies
Operational Variable
Instrument used to measure the variable. (Dependent)
Sources of knowledge
1.Personal Experience
2. Tradition
3. Authority
4. Research
Quantitative Research
Will have hypothesis. Empirical Data. Emphasizes numbers, measurement, deductive logic, and experiements.
Qualitative Research.
You will have questions. Narrative data. Subjective, can change you opinion. Flexible.
Qualitative Designs: Case Studies
in-depth study of a single program, event, activity, group.
Qualitative Designs: Phenomenology
Study a behavior
Qualitative Design: Ethnography
Go out and live among the group
Qualitatitive Design: Grounded theory
Develop a theory
True experimental
Subjects randomly chosen
not randomly chosen
Single Subject
One Subject is studied
Continuous Variable
measured on a scale that can take on an infinate number of values. (test scores, rubrics)
Categorical Variables
measured and assigned to groups on the basis of specific characteristics. (gender, grade level)
Operational definition
indication of a variable through the specification of the manner by which it is measured, categorized, or controlled. (I.Q. Test)
Examples of Extraneous Variables
Absences, Physical conditions, family structure, environmental, soci-economic, age.
Simple Random Sampling (Quanitative)
Each member of the population has the same probability of being selected.
Systematic Sampling (Quantitative)
Every nth member of the population is selected.
Stratified sampling (Quantitative)
Simple or systematic sampling in which the population is first divided into homogeneous subgroups. (LD, M, F, Grade)
Proportional Sampling
Not Equal
Disproportional Sampling
Equal amounts
Cluster Sampling
Naturally occuring groups are selected-usually geographically.
Nonprobability sample
Proability of selection not known
Convient Sample
Choose a group you can easily obtain information from (Your own class)
Purposive Sampling (Qualitative)
selection of particulary information or useful subjects.
Typical Case Sampling (Qualitative)
Representative subjects
Snowball sampling
selecting participants from recommendations of other participants.
Critical Case Sampling (Qualitative)
selecting the most important participants to understand phenomena being studied.
Purpose of sampling
Obtain generalizablity
Standard deviation
Average distance of the scores from the mean.
Percentile Rank
Percentage of scores at or below a specified score.
Measure of relationship between two or more quantitative variables
Positive correlation
Increases in one variable accompanied by increases in the other variable.
Correlation coefficient
Number between -1 and +1 that indicates the direction and strength of the relationship.