CHI-SQUARE TEST IN
ECOLOGY
Statistical work is important in IB Biology course as it
is commonly used for testing relationships between
categorical variables. Chi-square test is the most
frequently used one and its purpose is to show the
researcher if there is any correlation between two
variables by comparing the observed values obtained
through the experimental work with the expected values.
“In our Biology field trip, we visited the town of natural
blessings, rich flora and biodiversity as a whole, and
interesting socio-historical background: Kemaliye. In the
area of field study, I found fossilised sea shells remained
from millions of years ago, abandoned insect nidus, and
marbleised rocks. We also observed the local populations
of organisms like grasshoppers, caterpillars of moths or
butterflies, wasps, dung beetles and even a mini lizard.
We used certain techniques and equipment like forceps
and blowing in with aspirator. We also used binoculars
to observe Alpine choughs that performed like dancers
between the rocks and the sky.”
Elif KAYA
12- C
“For the third and last station we went to the Karanlık
Canyon. While you walk down through the canyon,
different sounds of birds come with you all the time.
Scientifically we walked under the sea. How nice to
imagine that!”
References
Durmus, Y. & Yapıcıoğlu, A. E. (2015). Kemaliye
(Erzincan) Ecology Based Nature Education Project In
Participants’ Eyes. Procedia - Social and Behavioral
Sciences, 197, 1134-1139.
Ayberk AYKUL
12- C
64
THE CLAPPER 2018 - 2019
The null hypothesis of the chi-square test indicates that
there is no relationship between the two variables.
The value obtained from the chi-square test allows the
researcher to compare it with the critical value and
consequently to reject or accept the null hypothesis. The
formula of the chi-square test is as following: