Establishing the Purpose &
Forming A Valid Hypothesis
Introduction to Research
Ms.Johny
What should the Purpose include?
The inclusion of the purpose (sometimes
called the objective) of the experiment
often confuses writers. The biggest
misconception is that the purpose is the
same as the hypothesis.
 Not quite. The purpose is broader, and is
a statement of what you expect to gain or
learn through the experiment.

What is a Hypothesis?
A hypothesis is a tentative statement that
proposes a possible explanation to some
phenomenon or event.
 A useful hypothesis is a testable
statement which may include a prediction.
 Please note that scientific writing is more
formal and is written in third person (the
investigator or the researchers) rather
than in first person (I or we).

How Are Hypotheses
Written?


Hypotheses take four formats:
a question, "Does temperature affect
fermentation?"
a conditional statement, "Temperature may affect
fermentation."
an “as” statement, “As temperature increases, as
production through fermentation will
also increase
an “If, then” statement, "If fermentation rate is
related to temperature, then increasing
the temperature will increase gas
production.
The format of a hypothesis includes the independent and
dependent variable (what is to be manipulated and what
is to be observed).
How Are Hypotheses Written?
a question,
"Does temperature affect
fermentation?"
a conditional statement,
"Temperature may affect
fermentation."
Writing A Hypothesis
an “as” statement,
“As temperature increases,
as production through
fermentation will also increase
an “If, then” statement,
"If fermentation rate is related
to temperature, then increasing
the temperature will increase
gas production.
The format of a hypothesis includes the independent and dependent
variable (what is to be manipulated and what is to be observed).
How Are Hypotheses Written?
The format of a hypothesis includes the independent and dependent
variable (what is to be manipulated and what is to be observed).
Are these Valid Hypotheses?
1.
2.
3.
4.
5.
6.
Chocolate may cause pimples.
Salt in soil may affect plant growth.
Plant growth may be affected by the
color of the light.
Bacterial growth may be affected by
temperature.
Ultra violet light may cause skin cancer.
Temperature may cause leaves to
change color.
Why or Why Not?
All of these are examples of hypotheses because they
use the tentative word "may.".
 However, their form is not particularly useful. Using the
word may does not suggest how you would go about
proving it.
 If these statements had not been written carefully, they
may not have even been hypotheses at all. For example,
if we say "Trees will change color when it gets cold." we
are making a prediction. Or if we write, "Ultraviolet light
causes skin cancer." could be a conclusion.
 One way to prevent making such easy mistakes is to
formalize the form of the hypothesis.

Formalized Hypothesis




A formalized hypothesis consists of an “If…Then..”
Statement and Two Variables. If the IV does this, then
the DV will do that. An “as” statement may also be
considered formalized. As the IV does this, then the DV
will do that.”
But not all if-then statements are hypotheses. For
example, "If I play the lottery, then I will get rich. This is
a simple prediction.
In a formalized hypothesis, a tentative relationship is
stated. For example, if the frequency of winning is
related to frequency of buying lottery tickets, "Then" is
followed by a prediction of what will happen if you
increase or decrease the frequency of buying lottery
tickets.
The ultimate value of a formalized hypothesis is it forces
us to think about what results we should look for in an
experiment.
Practice

Rewrite the first four hypotheses using the
formalized style shown earlier. Single
underline the dependent variable and
double underline the independent variable
in the If clause of each hypothesis.
Why is a Rationale
Statement Necessary?
A rationale statement provides a professional
argument for the hypothesis you are submitting.
 The rationale statement communicates the link
between the expected outcome, prior
knowledge, and new knowledge gained through
research.
 The hypothesis and rationale must enable
readers to understand your professional thinking
and understanding of the experiment.

What should the Purpose include?
The inclusion of the ________ (sometimes
called the objective) of the experiment
often confuses writers. The biggest
misconception is that the purpose is the
same as the hypothesis.
 Not quite. The purpose is ________, and
is a statement of what you expect to ___
or learn through the experiment.

What is a Hypothesis?
A hypothesis is a ________ statement that
proposes a possible explanation to some
phenomenon or event.
 A useful hypothesis is a _____ statement
which may include a __________.
 Please note that scientific writing is more
______ and is written in ____ person (the
investigator or the researchers) rather
than in _______ person (I or we).

How Are Hypotheses
Written?


Hypotheses take four formats:
a _________, "Does temperature affect
fermentation?"
a __________ statement, "Temperature may affect
fermentation."
an “__” statement, “As temperature increases, as
production through fermentation will
also increase
an “__, ____” statement, "If fermentation rate is
related to temperature, then increasing
the temperature will increase gas
production.
The format of a hypothesis includes the ________ and
__________ variable (what is to be manipulated and
what is to be observed).
Formalized Hypothesis




A formalized hypothesis consists of an “__________”
Statement and _______________. If the IV does this,
then the DV will do that. An “as” statement may also be
considered formalized. As the IV does this, then the DV
will do that.”
But not all ___________ statements are hypotheses. For
example, "If I play the lottery, then I will get rich. This is
a simple prediction.
In a formalized hypothesis, a __________ relationship is
stated. For example, if the frequency of winning is
_________ to frequency of buying lottery tickets,
"Then" is followed by a prediction of what will happen if
you increase or decrease the frequency of buying lottery
tickets.
The ultimate value of a ________ hypothesis is it forces
us to think about what results we should look for in an
experiment.
Why is a Rationale
Statement Necessary?
A _____________ provides a professional
argument for the hypothesis you are submitting.
 The rationale statement communicates the link
between the _____________, prior knowledge,
and ______________ gained through research.
 The hypothesis and rationale must enable
readers to ____________ your professional
thinking and understanding of the __________.
