STAT 101: Research Statistics with Computer

Application

NATURE OF
STATISTICS
PRELIMINARY TERM
SESSION 2

March 04, 2023

Learning Outcomes

•define the two general categories of statistics,

 descriptive and inferential statistics, and
•describe how they are used to summarize and make
decisions about data.
DIVISION OF STATISTICS
DESCRIPTIVE STATISTICS

• Consists of methods for organizing and summarizing information.

• A descriptive value for a population is called a parameter and a

descriptive value for a sample is called a statistic.
Example 1:
(a)80% of a class receives a passing grade.

(b)The Chicago Cubs had a winning record of 97-64 for the

2008 season.

(a)The U.S. won 11.92% of the Gold Medals in the 2008

Olympics.
Population & Sample

• A population is the collection of all individuals or items

under consideration in a statistical study.

• A sample is the part of the population from which

 information is obtained.
LET’S TRY THIS…
Respondents of the Study
The respondents of the study were the public
secondary school heads and teachers of the
selected secondary public schools in Calamba
East District.

Calamba East District has seven (7) public

secondary schools, namely: Calamba Bayside
National High School TechVoc, Calamba
Bayside National High School-SPA, Calamba
City Science High School, Calamba National
High School Main, Calamba National High
School Annex, Barretto National High School,
and Lecheria National High School.

The population and distribution of respondents is

presented in Table A.

Inferential Statistics
 • Consists of methods for drawing and measuring the
reliability of conclusions about a population based on
information obtained from a sample of the population.
Example 2:

(a)Political polling.

(b)Archaeological digs.

(c)Average salary of a football player.

LET’S TRY THIS!
Statement of the Problem
The study assessed the observance of the RPMS guidelines as assessed by the school heads
and teachers of Calamba East District and the teachers’ performance. This was the basis of the researcher
in developing an action plan that can enrich the observance of the RPMS and eventually improve the
performance of the teachers.
Specifically, the study sought answers to the following questions:
1.How do the school heads and teachers themselves assess the observance of the guidelines of the RPMS
with regard to:
. Performance Planning and Commitment,
. Performance Monitoring and Coaching,
. Performance Review and Evaluation, and
. Performance Rewarding and Development Planning?
2.What is the performance rating of teachers for school year 2014-2015? 3.What difference can be
determined between the assessments of the two groups of respondents on the observance of the guidelines
of the RPMS?
4.What relationship can be identified between the assessed observance of RPMS and teachers’
performance ratings?
5.What action plan can be offered to enrich the utilization of RPMS and to improve teachers’ performance?

LET’S PONDER!
Do we always need inferential statistics in our
research?
 When do we use descriptive statistics? How about inferential
statistics?
Descriptive vs. Inferential Statistics

(1) If the intent of the study is to examine and explore the

information obtained for its own intrinsic interest only, the
study is descriptive.
(2) If the information is obtained from a sample of a
population and the intent of the study is to use that
information to draw conclusions about the population, the
study is inferential.
LET’S TRY THIS…
 Classify the following studies as descriptive or inferential.
The 1948 Presidential Election -
Ticket Votes Perce
ntage

Truman-Barkley (Democratic) 24,179, 49.7

345

Dewey-Warren (Republican) 21,991, 45.2

291

Thurmond-Wright (States Rights) 1,176,12 2.4

5

Wallace-Taylor (Progressive) 1,157,32 2.4

 6

Thomas-Smith (Socialist) 139,572 0.3

Testing Baseballs –

• Major League Baseball used Spalding baseballs until 1976. In 1977, MLB began
using Rawlings baseballs (which are still in use today). In 1977, pitchers
complained that the baseballs were harder, bounced farther and faster, and
gave hitters an unfair advantage. An independent testing company randomly
selected a sample of 85 baseballs from the 1977 supplies of various major league
clubs. The bounce, weight, and hardness of the baseballs chosen was carefully
measured and compared with measurements obtained from similar tests on
baseballs used in 1952, 1953, 1961, 1963, 1970, 1973. The conclusion was that “…
 the 1977 Rawlings ball is livelier than the 1976 Spalding, but not as lively as it could
be under big league rules, or as the ball has been in the past.”

Music People Buy Rap/Hip hop 11.4

R&B/Urban 10.6

Country 10.5
• Results of monthly telephone
surveys yielded the percentage Religious 6.7

estimates of all music Jazz 3.4

expenditures shown in the table Classical 3.2

at the top of the next column. Soundtracks 1.4

These statistics were published in

New Age 1
2001 Consumer Profile.
Oldies 0.8
Music Type Expenditure (%)
Children's 0.5
Rock 24.4
Other 7.9
Pop 12.1
Unknown 6.1
 Dow Jones Industrial Averages -

• The following table provides the

closing values of the Dow Jones 1998 9,181.43

Industrial
1999 11,497.12
Averages as of the end of December
for the years 1997-2002. 2000 10,786.85

Year Closing Value

2001 10,021.50

1997 7,908.25 2002 8,341.63

Sources of Data
• The two main sources of data:
a. Primary data
- Data that come from an original source a.
Secondary data
- Data that are taken from previously recorded data
LET’S TRY THIS!
• Determine the sources of data in the given statement.

Since the primary objective of the study was to identify the implications of RPMS to the
performance of the teachers, the researcher found it necessary to utilize the performance
rating tool being used by the Department of Education (DepEd). This is the Results-Based
Performance Management System (RPMS). As for the secondary objective, which is to
assess the observance of the guidelines of the RPMS, the researcher used a survey-
questionnaire formulated only by the researcher wherein the indicators were based on the
RPMS guidelines given by the Department of Education (DepEd). All the indicators
presented in the researcher-made questionnaire was also aligned and followed the four-
phase cycle of the RPMS consistent with the Civil Service Commission SPMS.
CONSTANT AND VARIABLE
• There are two major characteristics of objects, people, or events
whether constant or variable.

CONSTANT
- A characteristic that does not vary.

VARIABLE
- A characteristic that can take of different values. It can vary in
quantity , or in quality.
TYPES OF VARIABLE
• There are two basically two types of random variables yielding two
types of data: qualitative and quantitative.
 QUALITATIVE VARIABLE
- Variable that is conceptualized and analyzed as distinct categories,
with no continuum applied

QUANTITATIVE DATA
- Variable that is conceptualized and analyzed along a continuum.
CLASSIFICATION OF VARIABLES
• Variables can be classified into two according to purpose whether
experimental or mathematical.
EXPERIMENTAL CLASSIFICATION
1. INDEPENDENT VARIABLE
- Variables controlled by the experimenter/researcher and expected to have
an effect on the behavior of the subject. 2. DEPENDENT VARIABLE
- Some measure of the behavior of the subject and expected to be
influenced by the independent variable.

Ex. To predict the value of fertilizer on the growth of

plants.
LET’S TRY THIS!
• Determine the independent and dependent variable. Statement of
the Problem
The study assessed the observance of the RPMS guidelines as assessed
by the school heads and teachers of Calamba East District and the
teachers’ performance. This was the basis of the researcher in developing
an action plan that can enrich the observance of the RPMS and eventually
improve the performance of the teachers.
• MATHEMATICAL CLASSIFICATION
- Variable may also be classified in terms of mathematical values they
may take on within a given interval.
1. CONTINOUS VARIABLE
- A variable which can assume any of an infinite number of values
and can be associated with points on a continuous line interval.
Ex. Height, weight, volume
2. DISCRETE VARIABLE
- A variable which consist of a finite number of values of countable
number of values.
Ex. Gender, courses, Olympic games
Measuring Variables

• To establish relationships between variables, researchers must observe

the variables and record their observations. This requires that the
 variables be measured.

• The process of measuring a variable requires a set of categories called

a scale of measurement and a process that classifies each individual
into one category.
4 Types of Measurement Scales
1. A nominal scale is an unordered set of categories identified
only by name. Nominal measurements only permit you to
determine whether two individuals are the same or
different.
QUALITATIVE VARIABLE CATEGORIES
Gender Male, Female
Automobile Ownership Yes, No
Type of Life Insurance Owned Term, Endowment, Straight-Life, Others,
 None

2. An ordinal scale is an ordered set of categories. Ordinal

measurements tell you the direction of difference between two
individuals.
QUALITATIVE VARIABLE CATEGORIES
Student class designation Freshman, Sophomore, Junior,
Senior
Product Satisfaction Unsatisfied, Neutral, Satisfied, Very
Satisfied
Movie Classification G, PG, PG-13, R-18, X
Faculty Rank Professor, Associate professor, Asst.
Prof, Instructor
Student Grades 1.0, 1.25, 1.50, 1.75, 2.00
3. An interval scale is an ordered series of equal sized categories.
Interval measurements identify the direction and magnitude of a
difference. The zero point is located arbitrarily on an interval
scale.
Qualitative Variable
Temperature (in degree C or F)
Calendar Time (Gregorian, Hebrew and Islamic)

4. A ratio scale is an interval scale where a value of zero indicates

none of the variable. Ratio measurements identify the direction
and magnitude of differences and allow ratio comparisons of
measurements.
Qualitative Variable
Weight (in pound or kilogram)
Age (in years or days)
Salary (in Philippine Scale)
CHARACTERISTICS OF LEVELS
OF MEASUREMENT
LEVEL OF MEASUREMENT PROPERTIES
Nominal Indicates a distinction
Ordinal Indicates a distinction
Indicates the direction of the distinction
Interval Indicates a distinction
Indicates the direction of the distinction
Indicates the amount of distinction
Ratio Indicates a distinction
Indicates the direction of the distinction
Indicates the amount of distinction
Indicates an absolute

THANK YOU!!!
 Cincy Merly B. Gecolea
c.gecolea@lcba.edu.ph
Fb- Pia Alexa Cassandra Gecolea