Nature of ScienceNature of ScienceScientific MethodScientific Method

These types of questions….These types of questions….

do not require knowledge of a specific do not require knowledge of a specific course.course.usually do not involve calculations.usually do not involve calculations.are 17/55 (31%) of the questions on the are 17/55 (31%) of the questions on the TAKS TestTAKS Testtend to require a lot of reading (don’t let tend to require a lot of reading (don’t let this scare you).this scare you).can mean an easy correct answer if you can mean an easy correct answer if you are willing to read!are willing to read!

Nature of Science VocabularyNature of Science Vocabulary

QuestionQuestionHypothesis/PredictionHypothesis/PredictionIndependent VariableIndependent VariableDependent VariableDependent VariableConstantsConstantsControl GroupControl GroupValidValidPrecisionPrecisionInference Inference ConclusionConclusion

Question?Question?According to these data, which According to these data, which question question was most likely answered was most likely answered by this activity?by this activity?

A How warm do materials get A How warm do materials get when placed in an electric when placed in an electric circuit?circuit?

B Will an electric current change a B Will an electric current change a metal into a nonmetal?metal into a nonmetal?

C Which material requires the C Which material requires the greatest voltage in an greatest voltage in an

electric circuit?electric circuit?

D Can an electric current be used D Can an electric current be used to distinguish metals from to distinguish metals from other materials?other materials?

HypothesisHypothesisA De-Icing ExperimentA De-Icing Experiment

Some species of plants that commonly grow near roadways are Some species of plants that commonly grow near roadways are used in an experiment. The plant species are divided into control used in an experiment. The plant species are divided into control groups and experimental groups. All groups are grown under groups and experimental groups. All groups are grown under identical conditions except that the experimental groups are given identical conditions except that the experimental groups are given daily applications of a de-icing solution that is used on roadways daily applications of a de-icing solution that is used on roadways in winter. At the end of one month, the growth of the control and in winter. At the end of one month, the growth of the control and experimental groups is compared.experimental groups is compared.

Which of the following is the most likelyWhich of the following is the most likely hypothesis hypothesis for the experiment for the experiment described above?described above?

A Vegetation that grows near roadways requires more water than vegetation A Vegetation that grows near roadways requires more water than vegetation in other areas.in other areas.

B De-icing solution causes roadways to have more space for vegetation.B De-icing solution causes roadways to have more space for vegetation.

C Vegetation near roadways changes the effectiveness of de-icing solution.C Vegetation near roadways changes the effectiveness of de-icing solution.

D De-icing solution affects some types of vegetation that grow near roadways.D De-icing solution affects some types of vegetation that grow near roadways.

Independent and Dependent Independent and Dependent VariablesVariables

A medical researcher hypothesizes that a newly A medical researcher hypothesizes that a newly developed medication can reduce high blood developed medication can reduce high blood pressure. Which of these would most likely be the pressure. Which of these would most likely be the dependent variabledependent variable in a study involving this in a study involving this medicationmedication??

A The number of participants in the study.A The number of participants in the study.B The ages of people treated for high blood pressure with B The ages of people treated for high blood pressure with

other medications.other medications.C The blood pressure of the participants in the study.C The blood pressure of the participants in the study.D The number of people treated for high blood pressure D The number of people treated for high blood pressure with other medications.with other medications.

ConstantsConstants

The table shows the time it took trees of the same type and size to The table shows the time it took trees of the same type and size to drop all of their leaves after being grown in different atmospheres. drop all of their leaves after being grown in different atmospheres. For the experiment to be valid, which of these must be a For the experiment to be valid, which of these must be a constant constant for all trees?for all trees?

F The height of all the trees during the entire experiment.F The height of all the trees during the entire experiment.

G The amount of water available to all trees during the experiment.G The amount of water available to all trees during the experiment.

H The mass of fallen leaves collected from each tree.H The mass of fallen leaves collected from each tree.

J The rate of photosynthesis in all trees during the experiment.J The rate of photosynthesis in all trees during the experiment.

Control GroupsControl Groups

A A validvalid study would include a study would include a control groupcontrol group containing— containing—

F bean seed, tomato seed, F bean seed, tomato seed, sunflower seed, and watersunflower seed, and water

G water and 2% root hormoneG water and 2% root hormone

H water onlyH water only

J bean seed, tomato seed, water, J bean seed, tomato seed, water, and 1% root hormoneand 1% root hormone

ValidValid Conclusion: Hearing aids are an effective way to Conclusion: Hearing aids are an effective way to

treat hearing loss.treat hearing loss.

A study was conducted to test the effectiveness of hearing A study was conducted to test the effectiveness of hearing aids. People with different types of hearing loss were aids. People with different types of hearing loss were included in the study. Which questionincluded in the study. Which question would help in would help in determining whether the conclusion above is determining whether the conclusion above is validvalid??

A What was the average age of people in the study?A What was the average age of people in the study?

B What was the most common occupation of people in the B What was the most common occupation of people in the study?study?

C How many people were included in the study?C How many people were included in the study?

D How many people in the study had vision problems?D How many people in the study had vision problems?

PrecisionPrecisionWhich of these will give the mostWhich of these will give the most preciseprecise measure measure of a 10-milliliter volume?of a 10-milliliter volume?

F H

G J

PrecisionPrecisionThe chart shows the density of seawater samples The chart shows the density of seawater samples collected from the Gulf of Mexico by four different collected from the Gulf of Mexico by four different groups. Which group’s data are most groups. Which group’s data are most preciseprecise??

A Group 1A Group 1

B Group 2B Group 2

C Group 3C Group 3

D Group 4D Group 4

InferencesInferences The graph compares absenteeism of The graph compares absenteeism of

elementary school students who elementary school students who wash their hands properly with wash their hands properly with absenteeism of students who fail absenteeism of students who fail to wash their hands properly. to wash their hands properly. Which Which inferenceinference could best be could best be supported by these data?supported by these data?

F Proper hand washing may F Proper hand washing may increase attendance among increase attendance among elementary school students.elementary school students.

G Older students have developed G Older students have developed better hand- washing habits than better hand- washing habits than younger students.younger students.

H Some elementary school classes H Some elementary school classes teach correct hand-washing teach correct hand-washing methods to students.methods to students.

J Improper hand washings is a J Improper hand washings is a common practice among most common practice among most elementary school students.elementary school students.

ConclusionConclusion

The data show how the mass of an undisturbed The data show how the mass of an undisturbed beaker of alcohol varied during a class period. beaker of alcohol varied during a class period. Which of the following is the best Which of the following is the best conclusionconclusion that can be made about the investigation?that can be made about the investigation?

A The beaker absorbed moisture from the air.A The beaker absorbed moisture from the air.

B A chemical change occurred in the beaker.B A chemical change occurred in the beaker.

C The beaker experienced a change of state.C The beaker experienced a change of state.

D Some material evaporated from the beaker.D Some material evaporated from the beaker.

Mass of beaker= 59.02 g

Think like a scientist!Think like a scientist!