stat rev Flashcards
Stato means?
Italian of State
The word statistics first appeared in print in
the book by
Gottfried achenwall
when was the theory of
probability utilized in relation to data
18600
is
the degree of likelihood for an event to
happen.
Probability
theory of probability has its beginnings
during the time of
Cardano, 1525
when was a certain Chevalier de Mere asked
an intriguing question that deals with
probability which provoked the fertile minds
of Blaise Pascal and Pierre de Fermat.
1654
the science of collecting, analyzing,
presenting, and interpreting data.
Statistics
Governmental
needs for ____ data as well as information about a
variety of economic activities provided much of the
early ____ for the field of statistics.
Census, Impetus
is the field of statistics that focuses on
quantitatively description of a collection
of data.
- It is usually used to define the basic
characteristics of the data in a study.
Descriptive statistics
It is used to make conclusions of the
probability that a difference between
samples is either reliable or by chance.
Inferential Statistics
describes a whole population
while a statistics described a sample of a
given population.
Parameter
a measure of “types”
and may be represented in terms of
characteristics, names, or symbols. Answer
the question “what” or “what type”
Qualitative Data
a measured of
“values”, or “counts” and expressed in
numerical values. Answer the question “how
many” and “how much”
Quantitative Data
data are in original form.
Raw Data
data collected is already
arranged in certain pattern such as in
ascending or descending order.
Array Data
are the characteristics of the
individual to be observed or measured.
Variables
– called the
predictor variable.
Independent Variable
Called the criterion Variable
Dependent Variable
– variables that
can be expressed in decimals.
Continuous variable
variables that cannot be expressed in
decimals.
Discrete or Discontinuous Variable
LEVELS OF MEASUREMENTS
Nominal Scale
Ordinal Scale
Interval Scale
Ratio scale
Data that consist of names, labels, or
categories only
The data cannot be arranged in an ordering
scheme
numbers or symbols are used to classify an
object or person to identify the group they
belong
Nominal Scale
Data contains the properties of nominal
level.
The data can be arranged in an ordering
scheme or ranked.
The difference between the values of the
data cannot be determined. The interval is
meaningless.
Ordinal Scale
Data contain the properties of ordinal
level.
Data values can be ranked.
The difference between the values of the
data are of known sizes.
The interval between the values has
meaning.
The “zero” does not imply the absence
of characteristics.
The ratio of data values are meaningless.
Interval Scale
Data contain the properties of interval
level.
The “zero” indicates the absence of the
characteristics under consideration
The ratio of data values has meaning.
Ratio Scale
Uncertainty is a part of our daily lives.
The branch of mathematics that deals with
uncertainty is the
Theory of Probablitity
number of ways 4 shows up
number of ways a balance die can fall =
1
6
well-defined results
Experiments
are all equally likely
or they occur by chance or randomly, it
is intuitively clear that they have equal
probabilities. Thus,
If an experiment has “n” equally likely
outcomes, then the probability of each
outcomes is 1
n
Outcomes
P (E) =
probability of event
Are data collected directly by the
researcher himself/herself.
Primary Data
Are information taken from
published and unpublished materials
previously gathered by other
researchers or agencies such as book,
newspaper, magazine, journals,
published and unpublished thesis and
dissertations.
Secondary Data
The 5 methods of data collection
Direct method
Indirect Method
Registration Method
Observation Method
Experimental Method
“interview method”
- done through a direct and
personal contact of the researcher
with the person from whom data
will be collected
Direct Method
“questionnaire method”
- Executed through the use of
either online questionnaire or
paper form questionnaires
distributed to groups of people.
Indirect Method
Done through the gathering
of data from concerned
offices.
- Example: PSA; Registrar
Office
Registration Method
Purely based on the subjective
remarks of the observer.
- It is applicable to data pertaining
to attitude, behavior, and values
of individuals.
Observation Method
The method that determines
the cause and effect
relationships of a certain
parameter or event under a
controlled condition.
- This method is usually used
by researchers in the field of
sciences.
Experimental Method
The complete set of individuals or
subjects
Population
Is just a representative of the whole
population.
Sample
How to get the sample size?
n = N / 1+N(e)²
n =
N =
e =
E=
n = sample size
N = population
e = margin of error
E= Events
Probability sampling
- Simple random sampling
- Systematic sampling
- Stratified sampling
- Cluster sampling
Non-Probability sampling
- Convinces sampling
- Voluntary response sampling
- Purposive sampling
- Snowball sampling
often times used when the population to be
considered is too large.
Restricted Random Sampling
There are two types of restricted random
sampling:
systematic sampling and
stratified sampling.
The selection of sample is done by
picking every k element of the th
population
k^th = N / n
Systematic Sampling
Is a process or activity that generates
data
STATISTICAL EXPERIMENT
Is an organized record of
measurements arranged in columns
and rows.
DATA SET
is a collection of one or more
outcomes of an experiment.
Event
ex: E = {TH, HT}
is the set/collection of all possible
outcomes in an experiment.
SAMPLE SPACE
is a function that associates a real
number to each element in the
sample space. It is a variable whose
values are determined by chance.
Random Variable
A random variable is a ___________________f its set of possible
outcomes is countable. Mostly,
discrete random variables represent
count data, such as the number of
defective chairs produced in a
factory.
Discrete Random Variable
A random variable is a ___________________ it takes on values
on a continuous scale. Often,
continuous random variables
represent measured data, such as
heights, weights, and temperatures.
continuous
random variable
EVERY UNIT HAS A ‘CHANCE’
OF BEING SELECTED, AND
THAT CHANCE CAN BE
QUANTIFIED.
Probability Sampling
EVERY ITEM IN A POPULATION
DOES NOT HAVE AN EQUAL
CHANCE OF BEING SELECTED.
Non Probability Sampling
TO PREVENT THE POSSIBILITY
OF A BIAS OR ERRONEOUS
INFERENCE, A RANDOM
SAMPLING IS COMMONLY
RECOMMENDED.
SIMPLE RANDOM SAMPLING
IN WHICH THE DRAWN PAPERS
ARE NO LONGER RETURNED IN
THE CONTAINER.
SAMPLING WITHOUT
REPLACEMENT
INVOLVES RETURNING TO THE
CONTAINER EVERY PIECE
DRAWN.
THIS ARRANGEMENT HOLDS THE
PROBABILITY CONSTANT. THUS, IF
WE HAVE 10 SLIPS OF PAPER, THE
PROBABILITY OF CHOOSING ONE
IN 10 IS MAINTAINED
THROUGHOUT THE PROCESS.
SAMPLING WITH
REPLACEMENT
THE ITEMS ARE ARRANGED IN
SOME WAY-ALPHABETICALLY
OR SOME SORT.
- A RANDOM STARTING POINT IS
SELECTED; AND THEN EVERY
k MEMBER WILL BE THE th
SUCCEEDING SAMPLES
- SYSTEMATIC RANDOM
SAMPLING
*A POPULATION IS FIRST DIVIDED
INTO SUBSETS BASED ON
HOMOGENEITY CALLED STRATA.
STRATIFIED RANDOM SAMPLING
*SAMPLES ARE SELECTED
PROPORTIONALLY FROM EACH
STRATUM WHICH CAN BE DONE
THROUGH SIMPLE OR
SYSTEMATIC RANDOM SAMPLING.
Stratified Random Sampling
CAN BE DONE BY SUBDIVIDING
THE POPULATION INTO SMALLER
UNITS AND THEN SELECTING
ONLY AT RANDOM SOME
PRIMARY UNITS WHERE THE
STUDY WOULD THEN BE
CONCENTRATED.
CLUSTER SAMPLING
