Nature of Science Scientific Method

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

Nature of Science Vocabulary QuestionHypothesis/Prediction Independent Variable Dependent Variable Constants Control Group ValidPrecisionInferenceConclusion

Question? According to these data, which question was most likely answered by this activity? A How warm do materials get when placed in an electric circuit? B Will an electric current change a metal into a nonmetal? C Which material requires the greatest voltage in an electric circuit? D Can an electric current be used to distinguish metals from other materials?

Hypothesis A De-Icing Experiment Some species of plants that commonly grow near roadways are used in an experiment. The plant species are divided into control groups and experimental groups. All groups are grown under identical conditions except that the experimental groups are given 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 experimental groups is compared. Which of the following is the most likely hypothesis for the experiment described above? A Vegetation that grows near roadways requires more water than vegetation in other areas. B De-icing solution causes roadways to have more space for vegetation. C Vegetation near roadways changes the effectiveness of de-icing solution. D De-icing solution affects some types of vegetation that grow near roadways.

Independent and Dependent Variables A medical researcher hypothesizes that a newly developed medication can reduce high blood pressure. Which of these would most likely be the dependent variable in a study involving this medication? A The number of participants in the study. 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. D The number of people treated for high blood pressure with other medications. with other medications.

Constants 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. For the experiment to be valid, which of these must be a constant for all trees? F The height of all the trees during the entire experiment. G The amount of water available to all trees during the experiment. H The mass of fallen leaves collected from each tree. J The rate of photosynthesis in all trees during the experiment.

Control Groups A valid study would include a control group containing F bean seed, tomato seed, sunflower seed, and water G water and 2% root hormone H water only J bean seed, tomato seed, water, and 1% root hormone

Valid Conclusion: Hearing aids are an effective way to treat hearing loss. Conclusion: Hearing aids are an effective way to treat hearing loss. A study was conducted to test the effectiveness of hearing aids. People with different types of hearing loss were included in the study. Which question would help in determining whether the conclusion above is valid? A What was the average age of people in the study? B What was the most common occupation of people in the study? C How many people were included in the study? D How many people in the study had vision problems?

Precision Which of these will give the mostprecise measure of a 10-milliliter volume? Which of these will give the most precise measure of a 10-milliliter volume? F H G J

Precision The chart shows the density of seawater samples collected from the Gulf of Mexico by four different groups. Which groups data are most precise? A Group 1 B Group 2 C Group 3 D Group 4

Inferences The graph compares absenteeism of elementary school students who wash their hands properly with absenteeism of students who fail to wash their hands properly. Which inference could best be supported by these data? The graph compares absenteeism of elementary school students who wash their hands properly with absenteeism of students who fail to wash their hands properly. Which inference could best be supported by these data? F Proper hand washing may increase attendance among elementary school students. G Older students have developed better hand- washing habits than younger students. H Some elementary school classes teach correct hand-washing methods to students. J Improper hand washings is a common practice among most elementary school students.

Conclusion The data show how the mass of an undisturbed beaker of alcohol varied during a class period. Which of the following is the best conclusion that can be made about the investigation? A The beaker absorbed moisture from the air. B A chemical change occurred in the beaker. C The beaker experienced a change of state. D Some material evaporated from the beaker. Mass of beaker= g

Think like a scientist!