Post on 31-Mar-2015
STATISTICALMETHODS I
STATISTICALMETHODS I
Prof. Elizabeth M. Role, Ph. D.
Prof. Elizabeth M. Role, Ph. D.
“It is not the capability you now possessor ever will have that will give you success; it is that which the Lord
will do for you.”
“It is not the capability you now possessor ever will have that will give you success; it is that which the Lord
will do for you.”
Ellen G. White
Theoretical Statistics
Applied Statistics
Types of
Statistics
Theoretical (Mathematical) Statistics• deals with the development, derivation, and proof of statistical theorems, formulas, rules, and laws.
Applied Statistics•Involves the applications of statistical theorems, formulas, rules, and laws to solve real-world problems.
APPLIED STATISTICS
CollectionCollectionPresentationPresentation
InterpretationInterpretationAnalysisAnalysis
Inferential Statistics
Descriptive Statistics
DIVISIONS OF APPLIED STATISTICS
Prob
ability
Descriptive Statistics•Consists of methods for organizing, displaying, and describing, data by using tables, graphs, and summary measures.
Inferential Statistics•Consists of methods that use sample results to help make decisions or predictions about a population.
Census Census
TERMINOLOGIES TERMINOLOGIES
PopulationPopulation SampleSample
Random SampleRandom Sample
Representative Sample
Representative Sample
Sample SurveySample Survey
Statistics Statistics
Survey Survey Element Element
Non-random SampleNon-random Sample
Data Data Variable Variable
Population is the collection of all elements whose characteristics are being studied.
Sample is a portion of the population of interest.
Element is a specific subject or object included in a sample or population.
Data is the collection of observations or measurements (value/score for an element) on a variable.
Data
Cross-section
Time-series
Cross-section data are collected on different elements at the same point in time or for the same period of time.
Time-series data give the values of the same variable for the same element at different points in time or for different periods of time.
Sources of DataExperiment
Survey
Experiment is the collection of data under controlled or modified environment.
Survey is the collection of data on the elements of a population or sample.
Census is a survey that includes all members of the population.
Luke 2The Birth of Jesus
1In those days Caesar Augustus issued a decree that a census should be taken of the entire
Roman world. 2(This was the first census that took place while Quirinius was governor of Syria.) 3And everyone went to his own town to register.
Sample survey is a survey that includes elements of a sample.
Representative sample is a sample that contains the same characteristics as the corresponding population.
Random sample is a sample drawn in such a way that each element of the population has some chance of being included in the sample.
Simple random sample is a sample drawn in such a way that each element of the population has the same chance of being selected for the sample.
Casting Lots
Casting the lot settles disputes and keeps strong
opponents apart.
Proverbs 18:18
The lot is cast into the lap, but its every decision is from the Lord.
Proverbs 16:33
Sampling with replacement
w/o replacement
With replacement – each element is put back in the population before the next element is selected.
Without replacement – occurs when the selected element is not replaced in the population.
Variable Types
Quantitative
Qualitative
Quantitative variable is a variable that can be measured numerically.
Variable is a characteristic under study that assumes different values for different elements.
QuantitativeContinuous
Discrete
Discrete variable is a variable whose values are countable.
Continuous variable can assume any numerical value over a certain interval.
Qualitative (categorical) variable cannot assume numerical values but is classified into two or more categories.
Levels of MeasurementLevels of MeasurementRatio
Interval
Ordinal
Nominal
Quantitative Qualitative