DATA MANIA
Data, Variables, Tables & Graphs
TWO TYPES OF DATA:
Qualitative Data – describes something with words only – no numbers – such as how
something looks, smells, sounds, feels or tastes. This type of data can’t be represented
on a graph.
Quantitative Data – uses measurement (numbers) to describe something. Fore
example, you can measure the length, mass, force, volume, pH, speed, or time of
objects.
EXPERIMENTS COLLECT DATA TO TEST VARIABLES
Manipulated (Independent) Variable – the thing that is deliberately changed by you to
determine that factor’s relationship to the responding variable. This is recorded in the
first column of the data table, and gets placed on the x-axis when graphing.
Responding (Dependent) Variable – the thing that changes in response to the
manipulated variable. This is what you measure during the lab. This data is recorded in
the second column of the data table, and placed on the y-axis when graphing.
Controlled Variables – are the conditions that are kept the same during an experiment
to ensure the data collected is reliable.
DATA IS RECORDED IN A TABLE
Data tables organize our data. Notice that the Manipulated Variable is in the first
column, and the Responding Variable is in the second column, with three trials below,
and an Average in the third column.
Title: Clearly state the purpose of the experiment [e.g., The effect of _____ (manipulated
variable) on _____ (responding variable)]
Manipulated
Variable &
Unit
Trial 1
Trial 2
Trial 3
Average of
3 Trials &
Unit
(x-axis)
Responding Variable & Unit
(y-axis)
IMPORTANT: Don’t forget to include units in EVERY box of the table (if possible)
DATA IS USED TO MAKE GRAPHS
We put data from tables into a graph to help show patterns and relationships in our
data easier.
TYPES OF GRAPHS
Line Graph – shows change over time (rate)
Pie Chart – shows percentage of a whole
Bar Graph – shows unchanging quantities
PARTS OF A GRAPH
Title – the title “graph” will not do. It should be the same title as your data table
Variables - Where do variables go? Remember: DRY-MIX: Plot the Dependent,
Responding variable on the Y-axis and the Manipulated, Independent variable
on the X-axis. This information comes straight from your data table.
Labeling the Axis - Both the X- and Y-axis must be labeled with a descriptor and
appropriate scales, including units. For example, don’t measure the height of
people in miles! ALL units will be given a METRIC abbreviation whenever possible.
Use a ruler when drawing the axes and the best-fit line on a line graph
PARTS OF A GRAPH
EVENLY SPACED SCALE
TITLE
Y-AXIS LABEL
responding variable
0
start
at 0
EVENLY SPACED SCALE
X-AXIS LABEL
manipulated variable