Post on 18-Jan-2016
CATALYST
1.Pick up your quiz #3 from the front of your graded work folder.
2.Update your quiz tracker!3.Catalyst: List some things that you have control over when you conduct an experiment.
SCIENTIFIC INQUIRYCONTROLS & GATHERING DATA
CONTROLS & GATHERING DATA 09.08.2008
TYPES OF EXPERIMENTAL CONTROLS (1)
1) Experimental group versus Control groups
Experimental group: treatment Control group: no treatment
Control group is necessary for a comparison
EXAMPLE OF TYPE 1Study What are the effects of vitamin C supplements
onthe number of colds a person gets per year?
Experimental GroupParticipants are given a vitamin C tablet
Control GroupParticipants in this group are not given anyvitamin tablet
CONTROLS & GATHERING DATA 09.08.2008
Control Types
1. Experimental Group (treatment) vs. Control Group (no treatment)
Ex. Vitamin C tablet vs. no tablet
TYPES OF EXPERIMENTAL CONTROLS (2)
2) Control over the levels or values of the independent variable
REMEMBER: Independent Variable: the variable you
are able to CHANGE or CONTROL Dependent Variable: that you can
measure which is affected by the independent variable
EXAMPLE OF TYPE 2Study What are the effects of vitamin C supplements
onthe number of colds a person gets per year?
Independent Variable The variable that we can change is the vitamin
C We can CONTROL or CHANGE the value of
vitamin C Changing the amount in each tablet
250 mg, 500 mg, 1000 mg Giving the same independent
variable to each participant
CONTROLS & GATHERING DATA 09.08.2008
Control Types
1. Experimental Group (treatment) vs. Control Group (no treatment)
Ex. Vitamin C tablet vs. no tablet
2. Control over levels/values of IV Ex. Amount of Vitamin C
TYPES OF EXPERIMENTAL CONTROLS (3)
3) Control over the experimental
setting
Preventing extraneous variables
EXAMPLE OF TYPE 3Controlling the noise in an
auditory perception experiment (how well people can hear)
CONTROLS & GATHERING DATA 09.08.2008
Control Types
1. Experimental Group (treatment) vs. Control Group (no treatment)
Ex. Vitamin C tablet vs. no tablet
2. Control over levels/values of IV Ex. Amount of Vitamin C3. Control over exp. Setting Ex. Noise level in exp.
TYPES OF EXPERIMENTAL CONTROLS (4)
4) Control Variable
A potential independent variable that is held constant across conditions in an experiment.
EXAMPLE OF TYPE 4
4) Control Variable
Question: Does the mass of a pencil affect the time it takes to fall to the ground?
Control Variable: You would drop the pencil from the same
height for every experiment.
Why?
CONTROLS & GATHERING DATA 09.08.2008
Control Types
1. Experimental Group (treatment) vs. Control Group (no treatment)
Ex. Vitamin C tablet vs. no tablet
2. Control over levels/values of IV Ex. Amount of Vitamin C3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held
constant/same in all trials Ex. Height of pencil in time
vs. mass exp.
The experimenter has an obligation to report ALL the results of an
experiment, NOT just those that support his/her hypothesis.
GATHERING DATAOBSERVE
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held
constant/same in all trials Ex. Height of pencil in time
vs. mass exp.
- Must report ALL data
GATHERING DATA ORGANIZE
Prepare a data table in your laboratory notebook
A data table ensures consistencyMakes it easier to analyze your results
TIPS FOR TABLE MAKING
Put a title at the top of every table Briefly describe what is contained
in the table. Include a table number at the start
of the table (such as Table 1.)
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held
constant/same in all trials Ex. Height of pencil in time
vs. mass exp.
- Must report ALL data- Create tables
- Title @ top
Use plain numbers. The units should go in the title instead of putting letters next to the numbers.
Don’t skip lines.
Label the columns and rows.
TIPS FOR TABLE MAKING
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
3. Control over exp. Setting Ex. Noise level in exp.4. Control Variable – held
constant/same in all trials Ex. Height of pencil in time
vs. mass exp.
- Must report ALL data- Create tables
- Title @ top- Label units @ top
Keep all the units the same Example: instead of 2 min 30 sec,
put 150 seconds
Use decimals, not fractions.
TIPS FOR TABLE MAKING
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
4. Control Variable – held constant/same in all trials
Ex. Height of pencil in time vs. mass exp.
- Must report ALL data- Create tables
- Title @ top- Label units @ top
- Keep all units same
Need to have IV on left column & DV on right column!
TIPS FOR TABLE MAKING
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
4. Control Variable – held constant/same in all trials
Ex. Height of pencil in time vs. mass exp.
- Must report ALL data- Create tables
- Title @ top- Label units @ top
- Keep all units same - IV on left; DV on right
EXAMPLE 1Hours of a Day Spent on Activities
Activity Hours
Sleep 6
School 6
Job 4
Entertainment
4
Meals 2
Homework 2
IV DV
EXAMPLE 2IV DV
EXAMPLE 3IV DV
CONTROLS & GATHERING DATA 09.08.2008
Control Types
Gathering Data
4. Control Variable – held constant/same in all trials
Ex. Height of pencil in time vs. mass exp.
- Must report ALL data- Create tables
- Title @ top- Label units @ top
- Keep all units same
PRACTICE (LEFT PAGE)Make a table that measures the number
of people in this classroom that have a birthday in each month.
YOU HAVE FOUR MINUTES TO GATHER THIS DATA.
PRACTICE (LEFT PAGE)Make a table that measures the number of people
in this classroom that have a birthday in each month.
Birth Month # People in Class
Jan.
Feb.
Mar.
Apr.
May
June.
July
August
Sept.
Oct.
Nov.
Dec.
IV DV
TABLE 1: # People in Class w/ Certain Birth Months.
SUMMARYTake 3 minutes to write a summary of today’s notes.
When done, work on your homework packet!