Texarkana Independent School District

Focus Plan

GRADING PERIOD: / 1st six weeks for all / PLAN CODE:
WRITER: / L. Petty / COURSE/SUBJECT: / 10th grade science
GRADE(S): / 10 / TIME ALLOTTED FOR INSTRUCTION: / 2 hours
TITLE: / Thinking Like a Scientist
LESSON TOPIC: / Setting up laboratory experiments using the scientific method.
TAKS OBJECTIVE: / Objective 1
The student will demonstrate an understanding of the nature of science.
FOCUS TEKS AND STUDENT EXPECTATION: / 10.2 The student uses scientific methods during field and laboratory
investigations. The student is expected to:
(A) plan and implement investigative procedures including asking
questions, formulating testable hypotheses, and selecting equipment
and technology
(D) communicate valid conclusions
10.3 The student uses critical thinking and scientific problem solving to make
informed decisions. The student is expected to:
(A) analyze, review, [and critique] scientific explanations, including
hypotheses and theories, as to their strengths and weaknesses using
scientific evidence and information
SUPPORTING TEKS AND STUDENT EXPECTATIONS: / If the next lesson in the sequence is used, 10.1a, 10.2b and 10.2c will also be covered.
CONCEPTS / ENDURING UNDERSTANDINGS/GENERALIZATIONS/PRINCIPLES
The student will understand that
Product use / Scientific experimentation affects products that are used in everyday life.
Validity / If experiments are not set up properly, incorrect or misleading information may be obtained.
Variables / Only one variable (the independent variable) may be changed in an experiment.
Constants / All other factors that may affect the experiment must be kept constant.
Reporting / Data from experiments (the dependent variable) will usually be reported in a properly set up data table and/or graph.
Controls / Every valid experiment must have a control group (a group kept under normal conditions that do not receive the independent variable.

I. SEQUENCE OF ACTIVITIES (INSTRUCTIONAL STRATEGIES)

A. Focus/connections/anticipatory set

As soon as roll is taken, the teacher should discuss with students that they will be doing an activity on the scientific method. The teacher should act like he/she is trying to find the paper. After about 1-2 minutes, the teacher should call a student to the front (pick one who does not seem very well-known) and explain that the papers are somewhere (either a neighboring teachers room or the office) and the teacher would like this student to go get them. Give the student the “pass” which should have a message that really tells the student where to go (A suggestions would be: “Ignore what you were just told. Go outside the classroom door where no one in class can see you and wait for someone to come get you.) Have the students take out a piece of paper, put their name on it and describe the person who just left in as much detail as possible. When everyone has had several minutes, collect all papers and invite the missing student back into the room. Read several descriptions, a couple close and some that are far off. Explain that observations are very important in science and that, making careful observations is a trait that must be practiced often. Explain that observations are also the first step of the scientific method but that each step must be carefully observed, or errors may occur.

B. Instructional activities

(demonstrations, lectures, examples, hands-on experiences, role play, active learning experience, art, music, modeling, discussion, reading, listening, viewing, etc.)

1. Lecture

Teacher should have already gone over the steps of the scientific method and the parts of an experiment

(see attached Transparency master) and Worksheet: Using the Scientific Method To Set Up Experiments.

C. Guided activity or strategy

Assign all students to work with their partner to complete Problem One on the activity. Give students several

minutes to do this. Many students will struggle with problem one because they will have a hard time

defending something that they know is false. Explain that, when these theories were originally proposed, humans had not identified oxygen yet, and did not know that oxygen was required to have a fire. It is easy to look back, now that we know the answer, and see how silly some ideas appear to be, but the knowledge was not known then.

Have students volunteer their answers for Problem One. Have them change their answers if they are not

correct.

In the same manner, working one problem at a time, have students complete the worksheet.

D. Accommodations/modifications

Struggling students should be paired with a gifted student.

E. Enrichment

Gifted students should help struggling students who may have problems with the lab set-up problems.

II. STUDENT PERFORMANCE

A. Description

As students complete the worksheet, they should show an increasing aptitude for picking out the correct answers. Since all students think differently, go over several different answers and discuss differences in how they answer questions, particularly on how they would set up labs. Try to get them to chose which one would be the best way to set up the experiment, don’t just give them the correct answer.

B. Accommodations/modifications

If students are struggling with note taking, the teacher may give them a copy of the Instructor’s Copy once

the discussion is over. Do not hand this out during the discussion!

C. Enrichment

None needed, although gifted students should show a thorough understanding over how to set up a lab by the

time the activity is completed.

III. ASSESSMENT OF ACTIVITIES

A. Description

The Worksheet: Using the Scientific Method To Set Up Experiments may be taken for a grade.

Teachers may elect to assign one or two problems from the activity Thinking Like a Scientist as a grade or

homework problem, or this may be used as a precursor to setting up an actual lab and just be used as a reference guide.

B. Rubrics/grading criteria

If a grade is to be taken on Thinking Like a Scientist, it would be best to assign the “Conclusion questions”

which summarize the material that was to be learned.

C. Accommodations/modifications

Struggling students may have trouble determine the difference between independent and dependent variables. Grading allowances may be made in this situation.

D. Enrichment

Gifted students may be given an additional assignment to write the actual procedure for one of the conclusion questions, or they may be asked to draw a data table for any of the situations given.

E. Sample discussion questions

1. What is an independent variable? The variable the scientist changes, what he/she is testing./

2. What is a dependent variable? What changes because of the independent variable, the results of the experiment.

3. What is a constant? Anything kept the same in an experiment. Everything except the independent variable.

4. Why are constants used in an experiment? To assure that the results are only due to the independent variable.

5. What is the experimental group? The group that is tested.

6. What is the control group? An identical group that is not tested.

7. Why are control groups used in an experiment? To assure that any results determined would not have happened unless it was due to the independent variable.

8. You want to determine whether vitamin C will prevent children from getting a cold. List the independent and dependent variables. List 5 things you must keep constant. Explain, briefly, how you will set up the experiment to assure that it is a valid experiment. (This question may be gone over or used as a quiz)

Independent variable – amount of vitamin C, dependent variable – whether children get colds (also accept answers dealing with severity of the cold, duration of the cold, how many colds are reported, etc.)

Constants – the ages of the children, the food the children eat, their environment, gender of the children, ethnic mix, exposure to germs, etc.) Set-up: Two identical groups should be tested. They should be kept in a controlled lab situation with identical environments, food, etc. They should have the same amount and type of exposure to the cold virus. All other factors should be identical. One group of children should be administered vitamin C, the other group should receive a placebo (sugar table). This would assure that the cold is not psychologically determined. Information on colds should be recorded. Students should be specific on the type of information they want to look for (frequency, severity, etc.) before they begin the experiment – the teacher may want to discuss this before hand.

IV. TAKS PREPARATION

A. Transition to TAKS context

Put the following data table on the board (or overhead). Give students time to answer the questions on a

piece of scratch paper. Go over the answers.

Conditions / Tank 1 / Tank 2 / Tank 3 / Tank 4 / Tank 5
Temperature (degrees C) / 21 / 25 / 21 / 20 / 23
Substance added / lead / lead / lead / copper / copper
Concentration (ppm) / 1.0 ppm / 1.5 ppm / 2.0 ppm / 1.0 ppm / 1.5 ppm
Type of fish / bass / bass / trout / Trout / catfish
Initial fish in tank / 20 / 25 / 30 / 50 / 10
Fish alive after 10 days / 15 / 20 / 20 / 49 / 4

A – true

B – false (and write an explanation)

C – cannot be determined from the information given (and explain)

_____ 1. You could conclude from this experiment that iron is killing the fish.

_____ 2. The water in the tanks has no effect on the number of fish that die.

_____ 3. Twice as many fish died in Tank #3 as in Tank #1 because the iron concentrations were

twice as high.

_____ 4. This is a valid experiment.

5. What is/are the variable(s) being manipulated?

6. What is/are the variable(s) that are kept constant?

Answers: 1 – C too many variables, nothing can be determined

2 – C too many variables, nothing can be determined

3 – C could have been the temperature

4 – B all valid experiments must have a control group and must have only 1 independent variable

5 – All variables are changed

6 – None are kept constant

Then, go through and have the students correct the set up. Extend and ask them what equipment they might

use and how they might run the experiment.

B. Sample TAKS questions

Spring 2003

1. Ten different types of culture media were inoculated with the same strain of bacteria and incubated at the same temperature. Nine of the cultures grew. Which of these conclusions can be drawn from this information?

(a) The media used in the experiment are all capable of sustaining bacterial growth.

(b) The temperature varied greatly during the experiment.

(d) One of the media lacked the nutrients needed for the bacteria to grow.

2. Using the data shown below, which conclusion is best supported by these data?

(a) Earth’s surface is composed mostly of silicon and calcium

(b) Oxygen is closer to Earth’s surface than aluminum.

(d) Silicon is much heavier than iron at Earth’s surface.

Most Abundant Elements at Earth’s Surface

Element / Percent by mass
Oxygen / 46.6
Silicon / 27.7
Aluminum / 8.13
Iron / 5.00
Calcium / 3.63

3. In an investigation 10,000 dung beetles were examined for the presence of parasites. The data showed that about 5% of the beetles had parasites. The results are ____.

(a) Invalid because only dung beetles were examined

(b) Unsupported because the parasite population was small

(d) Valid because the sample size was sufficient for accuracy

4. Certain chemicals in the diet of moth larvae seem to influence the early development of the moths’ wings. Careful observation of developing pupae could result in ____.

(a) data to verify the hypothesis

(b) changes to the conclusion

(d) development of a new moth species

V. KEY VOCABULARY

Conclusion Hypothesis

Constants Independent variable

Control group Law

Data Observation

Dependent variable Theory

Experimental group

VI. RESOURCES

A. Textbook

None needed.

B. Supplementary materials/equipment

Transparency master: Using the Scientific Method to Set Up An Experiment

Worksheet: Using the Scientific Method to Set Up An Experiment

Activity Information: Thinking Like a Scientist

Activity Worksheet: Thinking Like a Scientist

Instructor’s Copy: Thinking Like a Scientist

B. Technology

VII. FOLLOW UP ACTIVITIES

(reteaching, cross-curricular support, technology activities, next lesson in sequence, etc.)

A. Review of Skills

If the conclusion questions were assigned for a grade or for completion for homework, they should be gone over at this point.

B. Next Lesson in Sequence

At this point, students should be given an assignment to design a lab from scratch. The content material could be related to the class or it can be general. For example: IPC students could experiment to see how high a ball will bounce when dropped from 1 meter, Biology students could experiment to determine how jogging in place for 1 minute affects breathing or heart rate (it would be beneficial to assign readings every 15 seconds for 2 minutes so that graphing skills could also be practiced.), Chemistry students could be assigned how to determine the percent composition of sugar in bubble gum. It would also be advisable for students to write a lab from scratch each 6 weeks so that these skills are not forgotten, the activities should be related to material covered in that 6-week period. After the first 6 weeks, students should not receive papers with simple data tables, they should design their own as part of their grade (this may be extended in lower level class like IPC). Students should run the activity and turn in a final copy.

VIII. TEACHER NOTES

Before beginning lab, the teacher should:

1) Copy the transparency master

2) Run a class set of the Activity Instructions: Thinking Like a Scientist

3) Run class sets of the Worksheet: Using the Scientific Method to Set Up An Experiment and Activity Worksheet: Thinking Like a Scientist

4) Allow students the freedom to discuss differences that they may have in their set-ups. The hard part here, for teacher and student, is that there may be more than one valid way to set up an experiment. For example, on discussion question 8 – one group of students may decide to count how many colds the children receive and one may decide to test the severity or length of the cold. Unless this information is specified, both are valid. Students must learn to look for the BEST way to get an answer for their question because TAKS questions often give students lab setups for things they may not have studied and ask them how to set up the experiment. They must practice the wording they may come in contact with and they can only do this by practicing.