This document describes three experimental research designs: three-group design, parallel-group design, and counterbalanced or Latin square design. The three-group design involves three independent variable groups. The parallel-group design consists of a control group and two or more experimental groups that are compared to the control. The counterbalanced or Latin square design rotates treatments among subjects in a systematic way so that each treatment occurs in each position an equal number of times. Examples are provided to illustrate how each design could be applied.

1. •Three-Group Design
•Parallel-Group Design
•Counterbalanced or Latin Square Design

2.  In this design, there are three groups of
independent variables.

3. Illustration 1 (Experimental Research)
Suppose the researcher wishes to conduct a study on
the effect of using direct seeding, transplanting, and using
stem cuttings in growing of Moringa Oleifera at the
municipal grounds of Barotac Viejo. These three methods of
culturing Moringa Oleifera are independent variables and
the dependent variable is the weight of Moringa Oleifera.
Mean and ANOVA, two-factor or F-test: two-factor are the
statistical tools used. Mean is used to determine the mean
weight of Moringa per method. ANOVA or F-test is used to
test the significant difference on the weight of Moringa of
the three methods. If significant difference exists, this
means the three methods of growing Moringa Oleifera
really differ with each other because one method is most
effective. If insignificant difference exists, hence, the
weight of Moringa Oleifera using the three methods are
almost the same.

4. Table 5.1. Sample of Three-Group Design on the Effect
of Using Direct Method, Transplanting Method
and Using Stem Cuttings in Growing Moringa
Oleifera at the Municipal Grounds of Barotac
Viejo

5. Illustration 2 (Descriptive Research)
Suppose the researcher wishes to conduct a study on the effectiveness of
teaching English using grammar translation method, direct method, and
audio-lingual method to first year college students at the State
Universities and Colleges (SUCs) in Region VI (Western Visayas). The
three methods of teaching English are independent variables and the
scores of students per method are dependent variables. The students
are exposed to the three methods of teaching English with one teacher.
Mean and ANOVA: two-factor of F-test: two-factor are the statistical
tools used. Mean is used to determine the mean score of the students
per method. ANOVA: two-factor is used to determine the significant
difference of the scores using the three methods of teaching English. If
significant difference exists, this means the methods of teaching English
really differ with each other because one method is most effective. If
insignificant difference exists, thus, the methods of teaching English are
almost the same.

6. Table 4.17. Sample of Three-Group Design on the Effectiveness of
Teaching English using Grammar Translation Method,
Direct Method, and Audio-Lingual Method to First Year
College Students at the State Universities and
Colleges (SUCs) in Region VI

7.  This type of experimental design consists of
three or more groups wherein one group is
control group with two or more
experimental groups. The control group or
parallel group serves as basis of the
experimental groups which is manipulated
or changed, but the experimental groups
vary.

8. Illustration 1 (Experimental Research)
Suppose the researcher wishes to conduct a study on the
effectiveness of culturing commercial catfish using, soybean
meal, meat and bone meal, blood meal, and fish meal as
protein supplements. Fish meal is the control group or
parallel group and the experimental groups are meat and
bone meal, blood meal, and soybean as protein supplements.
Mean and ANOVA: two-factor or F-test: two-factor are the
statistical tools used to determine the mean weight of catfish
and significant difference on the mean weight. If significant
difference exists on the mean weight of catfish, this means
protein supplements really differ on the weight of catfish
because one protein supplement is most effective. If
insignificant difference exists, thus the weight of catfish using
the four protein supplements are almost the same.

9. Table 5.2. Sample Parallel-Group Design on the
Effectiveness of Culturing Commercial
Catfish Using Soybean Meal, Meat and
Bone Meal, Blood Meal and Fish Meal as
Protein Supplements
(Experimental Group)

10. Illustration 2 (Descriptive Research)
Suppose the researcher wishes to conduct a study on the
effectiveness of teaching Chemistry using traditional method and
two modern methods in Third Year Secondary students at the
Iloilo National High School. Traditional method is the control
group and two modern methods of teaching Chemistry are
experimental groups. The students are exposed to the three
methods of teaching Chemistry under one teacher. Mean and
ANOVA: two-factor or F-test: two-factor are the statistical tools
used. Mean is used to determine the mean score of students per
method. ANOVA or F-test is used to determine the significant
difference on the scores of students using the traditional and
two modern methods of teaching Chemistry. If significant
difference exists, this means the three methods of teaching
Chemistry to Third Year Secondary students really differ with
each other because one method is most effective. If insignificant
difference exists, thus, the methods of teaching Chemistry are
almost the same.

11. Table 4.20. Sample Parallel-Group Design on the
Effectiveness of Teaching Chemistry Using
Traditional and Two Methods to Third Year
Secondary Students at the Iloilo National
High School
(Experimental Group)

12. This design is also called “rotation design”. It
involves an exchange of two or more treatments
taken by the subjects during the experiment. The
arrangement employed in the design is Latin
square in which each variable is a form of square
occurring once in each row or column. This is
called quasi-experimental design.

13. Illustration 1 (Experimental Research)
Suppose an investigator wishes to determine the
effectiveness of growing squash using four different organic
fertilizers to four different nurseries. Due to different ecological
parameters such as light, humidity, temperature, and oxygen of
each nursery, each is required to have one organic fertilizer. The
first treatment combination consists of OF₁, N₁, and G₁ where SF
stands for Organic Fertilizer; N, Nursery; and S, Squash or
scientifically called Cucurbita. The second combination is OF₁, N₂,
S₂ and so on. It will be noted that “S₄” or grouper is the diagonal of
the square and appears in each position from first supplemental
feed to the fourth organic fertilizer. F-test or analysis of variance
(ANOVA) is used to determine the significant difference on the
effectiveness of growing squash using four different organic
fertilizer to four different nurseries.

14. Table 4.17. Sample of Counterbalanced or Latin Square
Design in Growing Squash Using Four
Organic Fertilizers to Four Nurseries
N₁ N₂ N₃ N₄
OF₁ S₁ S₂ S₃ S₄
OF₂ S₂ S₃ S₄ S₁
OF₃ S₃ S₄ S₁ S₂
OF₄ S₄ S₁ S₂ S₃

15. Illustration 2 (Descriptive Research)
Suppose the researcher wants to determine the
effectiveness of the four technological innovations in teaching
Social Sciences taught by four professors to four groups of
students. Each professor is required to use each method of
reward. The first treatment combination consists of TI₁, P₁, S₁
where TI stands for technological innovation; P, professor; and
S, student. The second combination is TI₁, P₂, S₂ and so on. Take
note that “S₄” is the diagonal in a square and it appears in each
position from the first position to the fourth method. F-test or
ANOVA is used to determine the significant difference on the
effectiveness of the four technological innovations in teaching
Social Sciences taught by four professors.

16. Table 5.10. Sample of Counterbalanced or Latin Square
Design in Teaching Social Sciences Using
Four Technological Innovations Taught by
Four Professors
P₁ P₂ P₃ P₄
TI₁ S₁ S₂ S₃ S₄
TI₂ S₂ S₃ S₄ S₁
TI₃ S₃ S₄ S₁ S₂
TI₄ S₄ S₁ S₂ S₃