Transcript EXPERIMENTAL RESEARCH - Near East University

• Quantitative Research helps researchers to prove
their educational or psychological
phenomena/hypothesis as true or false.
Quantitative research also provides evidence via
objective observations which are related with
phenomena/hypothesis (Mertens, 1998).
• Quantitative Research provides statistical
(numerical) information with percentages,
graphs, charts, etc. and describes findings with
numbers counter to Qualitative Research which
describes findings with words.
Qualitative
Quantitative
• Experimental Research takes part in
Quantitative Research Approaches. (Mertens,
1998, Airasian et al, 2006)
• We are teachers, tutors, instructors or educators,
but all of us are related with education. We may
detect a problem while we are in classrooms or at
home. Learner or learners may have a problem
about something. After that we can talk this
problem with other teachers and we may find out
that other learners have same problems, then we
can search it simply on internet. Again we can
find out similar statements on internet. After a
while we can design a treatment or teaching
strategy to solve the problem. We should check
our new strategy/treatment if it is useful and
valid. EXPERIMENTAL RESEARCH.
Process
• While doing Experimental Research, the steps are
actually as like as other research types.
• The researcher selects and defines the problem, does
literary analysis, selects participants, decides
measuring instruments, prepares research plan,
collects data, analyzes data, and presents the results.
• The researcher should have at least one hypothesis.
The hypothesis determines what kind of difference is
expected to occur between the independent and
dependent variables to be able to support or refute the
hypothesis.
• Airasian et al (2006) mentioned that there are
three types of comparing independent and
dependent variables as following;
– Comparing two different methods (effects of
Computer-based and teacher-based teaching)
– Comparing a new method and traditional method
(New hand-writing method vs traditional handwriting method)
– Comparison of different amounts of single method
(the effect of 20-min speaking session versus 40mins speaking session)
• In Experimental Research Studies, there are
two variables which are called;
– Dependent (Control) variable,
– Independent (Treatment/Experimental) variable.
Independent
(Treatment/Experimental) Variable
• One of the group that researcher manipulates
and applies his/her new strategies. The
researcher tries to prove that his/her strategy
is better or different than others.
• In educational research with experimental
resaerch, researcher manipulates to method,
instruction, arrangement of learning
classroom, materials and duration of
treatment. (Airasian et al 2006)
Dependent (Control) Variable
• Traditional method or different method is
applied on control variable. This group is here
to be able to observe what kind of differences
occurs in the independent group.
• Characteristic features (such as gender, age, level
of learners...etc) and other features (classroom
resources, time of lessons,etc) are equal and only
the teaching strategy is different between the two
groups to be able to measure and analyze the
effects of teaching strategy.
• The researcher selects and identifies the groups,
• The researcher decides which group take which
strategy,
• The researcher controls every condition
• The researcher tests, observes, compares the
dependent and independent variables, then
presents the differences between these groups,
finally states if his/her hypothesis is supported or
refuted by the results.
• The most important role of the researcher is to be
sure about dependent and independent groups
have equal conditions and the only different thing is
the treatment or teaching strategy (or what is
related with hypothesis)
Validity and Reliablity
• There are Internal Validity and External Validity
in Experimental Research.
• Internal Validity: Airasian et al (2006) defines it
as “the degree which observed differences on
the dependent variable are a direct result of
manipulation of the independent variable, not
some other variable” (p.598).
• External (ecological) Validity: Airasian et al 2006
defines it as “the degree to which study results
are generalizable, or applicable to groups and
environments outside the experimental
setting”(p.597).
• To achieve maximum internal validity, the
researcher should control everything (on
participants, teachers, members of dependent
group ..etc.) and create laboratory environment
in the school. But if the researcher achieve
maximum internal validity then the research
study has poor reality and generalizability.
Although, if the researcher tries to achieve
maximum external validity, then the researcher
cannot control independent and dependent
groups. Thus researcher should balance external
and internal validity.
• The researcher can first do his/her research with
maximum internal validity and then, the
researcher can redo it with external validity to
test the internal validity to be sure that findings
are generalizable (Airasian et al, 2006)
Threats to Internal Validity
1. History: It refers to any event that occurred
during the experimental research study and it
affected the results of the study. Make the
other group to experience with same event
can help the researcher to solve the problem.
e.g. If the researcher gives chocolate to students
who read a book, he/she should give same
thing in both dependent and independent
groups.
2) Maturation: refers to psychological and biological
changes during the study which may affect
participants’ performance. (such as becoming
stronger, older, wiser, bored or tired) . If both
independent and dependent groups experienced with
same maturation factors, then it is not a problem.
3) Testing: This problem occurs when the researcher
uses pre-test and post-test in research study. When
participants took pre-test, they became familiar with
test, to be able to solve this, both independent and
dependent groups take both pre and post-tests. The
participants also focus on only test questions so the
researcher may not decide new teaching strategy is
better or they are familiar, so there should be time
between pre and post-tests to solve this threat.
4) Instrumentation: happens when the researchers
used pre-tests and post-tests with different
difficulty levels, different observation tools and
mechanical device failures in experimental
research studies. The researcher can solve the
problem with using pre-tests and post-tests in
same difficulty level, using only one observation
tools and be careful about the mechanical devices.
5) Statistical Regression: occurs when the researcher
chooses from only extremely low or high level
students as participants. Extremely Low level
participants cannot perform lower and extremely
high level ones cannot perform better.
6) Differential Selection of Participants: The
researcher should arrange the independent and
dependent groups with equal characteristics. If the
researcher does not do this, results are not valid.
(for ex. In one classroom, all of the students may be
very successful in English and the other classroom
may be beginners, in one classroom older students,
in the other classroom younger). To solve it, the
researcher can divide all participants first gender,
then age and then their grades.
7) Mortality: Participants may drop out the research
study for any reason and this may affect the results.
To solve this problem and keep groups’
characteristics similar, the researcher can remove a
participant with same characteristics who dropped
out from other group.
Threats to External Validity and other
threats on validity
1) Multiple-Treatment Interference: occurs when the
same participants receive more than one
treatment. Participants may be under effects of
earlier treatment. This limits the generalizability.
2) Selection-Treatment Interaction: occurs when the
participants of a variable react differently to the
treatment than other potential participants in the
population reacted or accessible population is
different than the researcher’s target population.
(e.g. The researcher is not accepted from 3 schools
which fits to researcher’s population sample
requirements and 4th school may accept the
researcher which does not fit.)
3) Pre-test-Treatment Interaction : Pre-test may make
participants notice the treatment and they may become
more sensitive and interested in pre-test subjects while
receiving the treatment. This may affect participants results
and it may be different if they have not had pre-test. This
affects generalizability. (while watching a film for educational
purposes, pretested group may observe the film and the
group without pre-test may enjoy the film as a comedy film).
4) Treatment Diffusion: Participants of dependent and
independent groups’ may speak with each other and they
can learn from each other. Automatically, participants may
use traditional or new strategy items which is not valid.
Teachers can also learn from each other and uses in their
classrooms. To reduce this, the researcher can warn teachers
not to speak about new strategy and control the students to
reduce speaking rates.
5) Experimenter Effects: The researcher’s their
own threat on their own research study. If the
researcher knows some participants, and their
performance, the researcher may evaluate
differently. To solve it, the researchers can use
blind-scoring where you do not know which
test paper belongs to whom.
• Reactive Arrangements (Participants’ effects):
occurs when participants act differently than
expected.
• John Henry Effect: John Henry worked for a
railroad company. He was a steel drivin’ man and
when he heard that a steam powered machine is
going to take him and his team’s place he worked
hard to provide he was better than machine, as
like as this students who believes that traditional
way is better, they could behave atypically or
they might not accept the new treatment.
• Placebo effect : Medical researchers use this.
Subjects take water and sugar instead of real
medicine and again they can feel better, in
experimental research, subject may look like
perform better with new strategy but it might not
be the reality.
• Novelty effect: New treatment/strategy may
increase learners’ interest, motivation and
participation to the lesson. But, the researcher
should be sure about if the strategy is really
beneficial or it is just a new and different way
which isinteresting for learners. To be able to solve
this problem the researcher should apply the new
strategy till it becomes quite old for students.
• Thank you 
References
• Airasian, P., Gay, L. R., & Mills, G. E. (2006). Educational
Research; Competencies for Analysis and Applications
(8th Edition ed.). Upper Saddle River, New Jersey, USA:
Prentice Hall.
• Mertens, D. M. (1998). Research Methods in Education
and Psychology: Integrating Diversity with Quantitative
& Qualitative Approaches. (C. D. Laughton, Ed.)
Thousand Oaks, California, United States of America:
SAGE Publications.
• The Variables Song [Video File]. Retrieved 20.12.2012
from
http://www.youtube.com/watch?v=Hxbz656Euyw