Controlvs Constant

							                                                      Teacher Page
Control vs. Constant:
A Strategy to Understand their Differences

Pre—     students use a highlighter to highlight what they
         think are relevant definitions of the two terms

Mid—     students check their definitions, correct them if
         necessary and then draw pictures that will help
         them remember the words “control” and
         “constant”; a suggestion is to have them draw pics
         of labs they have done already that have constants
         and controls

Post--   students will practice identifying the controls and
         constants in several examples
                                                                                                        Student Page
Control vs. Constant

Often students confuse, misunderstand or interchange two important elements of the scientific method:
controls and constants. It is easy to see two words that both start with the same “con” and both are used
in the scientific method. In order to recognize the differences, please complete the following.

Read the two definitions below and highlight any/all parts of the definitions that are relevant
(important) to science.
                                                                     control.
Dictionary.com Unabridged (v 1.1) –
                                                                 16. Philately. any device printed on a postage or
                                                                     revenue stamp to authenticate it as a
con·trol kənˈtroʊl - Show Spelled                                    government issue or to identify it for
Pronunciation[kuh n-trohl] Pronunciation Key -                       bookkeeping purposes.
Show IPA Pronunciation verb, -trolled, -trol·ling,
noun                                                             17. a spiritual agency believed to assist a
                                                                     medium at a séance.
–verb (used with object)
      1. to exercise restraint or direction over;                18. the supervisor to whom an espionage agent
          dominate; command.                                         reports when in the field.

     2. to hold in check; curb: to control a horse; to     Dictionary.com Unabridged (v 1.1)
        control one's emotions.

     3. to test or verify (a scientific experiment) by a   con·stant ˈkɒn stənt - Show Spelled Pronunciation[kon-
        parallel experiment or other standard of           stuh nt] Pronunciation Key - Show IPA Pronunciation
        comparison.                                        –adjective
     4. to eliminate or prevent the flourishing or               1. not changing or varying; uniform; regular;
        spread of: to control a forest fire.                         invariable: All conditions during the three
                                                                     experiments were constant.
     5. Obsolete. to check or regulate (transactions),
        originally by means of a duplicate register.             2. continuing without pause or letup; unceasing:
                                                                     constant noise.
–noun
     6. the act or power of controlling; regulation;             3. regularly recurrent; continual; persistent: He
        domination or command: Who's in control                     found it impossible to work with constant
        here?                                                       interruption.
     7. the situation of being under the regulation,             4. faithful; unswerving in love, devotion, etc.: a
        domination, or command of another: The car                  constant lover.
        is out of control.
                                                                 5. steadfast; firm in mind or purpose; resolute.
     8. check or restraint: Her anger is under
        control.
                                                                 6. Obsolete. certain; confident.
     9. a legal or official means of regulation or
        restraint: to institute wage and price controls.
                                                           –noun
     10. a standard of comparison in scientific                  7. something that does not or cannot change or
         experimentation.                                           vary.
     11. a person who acts as a check; controller.               8. Physics. a number expressing a property,
                                                                    quantity, or relation that remains unchanged
                                                                    under specified conditions.
     12. a device for regulating and guiding a
         machine, as a motor or airplane.                        9. Mathematics. a quantity assumed to be
                                                                    unchanged throughout a given discussion.
     13. controls, a coordinated arrangement of such
         devices.                                          —Synonyms 1. unchanging, immutable, permanent. 2.
                                                           perpetual, unremitting, uninterrupted. 3. incessant,
     14. prevention of the flourishing or spread of        ceaseless. 4. loyal, staunch, true. See FAITHFUL. 5. steady,
         something undesirable: rodent control.            unwavering, unswerving.
                                                           —Antonyms 1. changeable. 2. fitful. 3. sporadic. 4.
     15. Baseball. the ability of a pitcher to throw
         the ball into the strike zone consistently:       unreliable
         The rookie pitcher has great power but no
                                                                                                      Student Page
Now read the following two definitions. Do your highlighted choices seem to fit? If no, please go
back up and correct them.

The American Heritage Science Dictionary
control (kən-trōl') Pronunciation Key
A standard of comparison for checking or verifying the results of an experiment. In an experiment to test the
effectiveness of a new drug, for example, one group of subjects (the control group) receives an inactive substance
or placebo , while a comparison group receives the drug being tested

The American Heritage Science Dictionary
constant      (kŏn'stənt)
A quantity that is unknown but assumed to have a fixed value in a specified mathematical context. A theoretical or
experimental quantity, condition, or factor that does not vary in specified circumstances. Avogadro's number and
Planck's constant are examples of constants.


Next you are going to make a picture that will remind you of the word and its definition…

CONSTANT




CONTROL
                                                                                                         Student Page
Finally, read the following and answer the questions.

Example:

An electromagnet will pick up more nails if more batteries are put in the circuit.
The number of batteries can be changed to determine its effect on the electromagnet.
        Independent Variable-number of batteries in a circuit
         Dependent Variable-number of nails the electromagnet picks up
         Constants-type of battery, size and amount of wire, type of connection, type of circuit, size and type of
                   paper clips, procedure for picking up the clips
         Control—number of nails picked up with 1 battery



Now, it’s your turn.

1. Apple trees that receive the most water will produce the largest apples.
The amount of water can be changed to determine its effect on the size of the apples grown.
    a. Independent Variable-

    b. Dependent Variable-

    c. Constants-



2. Students will score better on spelling tests by increasing the number of minutes each student studies.
The amount of time can be changed to determine its effect on the spelling scores.
    a. Independent Variable-

    b. Dependent Variable-

    c. Constants-age of student, gender of student, time of test, test giver, study method

    d. Control—


3. What is the effect of the amount of salt on the height an egg floats?
    a. Constants-

    b. Control—


4. What is the effect different liquids have on an object floating in liquid? The liquids used are corn oil, milk, soda
  pop, water, orange juice, and tomato juice.
    a. Constants-

    b.   Control—