Presenting Scientific Data
PHYSICAL SCIENCE
CREATING AND INTERPRETING GRAPHS
Many people have pets. One survey of pet owners showed the
following breakdown of the type of pets owned: 35% dogs; 35%
cats; 10% birds; 5% hamsters, gerbils, mice, rats; 5% reptiles;
and 10% other.
1. Copy the incomplete circle graph below on your paper.
Complete the graph using the survey data. Estimate the
angle of each section of your completed circle graph.
Give your graph a title and label what
each section of the graph represents.
2. Explain how viewing the graph conveys
information to the reader more quickly
than reading the list of data.
PREVIEWING
c. Scaled bars used to represent
various measurements
b. Showing how a variable responds to
changes in another
d. Comparing a similar
set of data
e. A divided circle, with each “slice”
representing a proportional fraction
f. Showing how a part relates to
the whole
a. Variable y is plotted vs. variable x.
DATA TABLES
Using a table is a simple
way to present data
visually.
 The table relates two
variables – a
manipulated variable
(location) and a
responding variable
(average annual
precipitation).

LINE GRAPH
What is the
volume of 3g
of water?
3cm3
‘rise’ =
change in the
y-variable
‘run’ =
change in
the xvariable
What is the mass
of 9 cm3 of
water?
9g
Plotting the mass
of water against
the volume of
water yields a
straight line.
Useful for showing changes that occur in related variables.
IMPORTANT VOCABULARY

The mass of the water is directly proportional to the volume,
meaning that the ratio of two variables is constant.


(if one goes up, the other goes up)
An inverse proportion is a relationship in which the product of 2
variables is a constant =

(if one goes up, the other goes down)
Each point on the
graph above
represents the same
volume of water: 1
gallon.
BAR GRAPHS & CIRCLE GRAPHS
Useful for comparing several
measurements, amounts of
changes.
CELSIUS, KELVIN AND FAHRENHEIT
(1) Celsius Scale – widely used in chemistry
and the everyday scale of temperature in
most countries.
 0C
is the freezing point of water
 100C is the boiling point of water at sea level.
CELSIUS, KELVIN AND FAHRENHEIT
(2) Kelvin Scale – is the SI scale and is based
solely on the properties of gases.
 Used
in most calculations.
 0 (zero) is the lowest attainable temperature on
this scale and is referred to as ABSOULUTE ZERO. It
is equivalent to –273.15C. On the Kelvin scale water
freezes at 273 K and boils at 373 K.
CELSIUS, KELVIN AND FAHRENHEIT
(3) Fahrenheit Scale – the common temperature
scale in the United States which is not generally
used in scientific studies.

Water freezes at 32F and boils at 212F.
CELSIUS, KELVIN AND FAHRENHEIT
You will need to know how to convert among all three
temperature scales. These are the formulas that you will
need to MEMORIZE!
K =  C + 273.15
 C = 5/9 (  F - 32)
 F = 9/5 (  C) + 32
*Remember to always do what is in parenthesis first!
TEMPERATURE CONVERSION EXAMPLE
Liquid nitrogen, which is often used as a coolant for lowtemperature experiments, has a boiling point of 77K. What is
the temperature on the Fahrenheit scale?
 First convert 77K to Celsius:


Tc=Tk-273.15 = 77-273.15= -196oC
Next convert Celsius to Fahrenheit


 F = 9/5 (  C ) + 32
 F = 9/5 (-196oC) +32 = -320.8  F