The Scientific Process:

Scientific Method is a series of steps that is used to answer a question or solve a problem.

The Scientific Process:

6 Steps to the Scientific Method: 1) Problem

The question or problem is based on observations. In this stage, the

scientists recognizes that something has happened and that is occurs repeatedly.– Example: My neighbor’s plants growing better than mine.

The Scientific Process:

6 Steps to the Scientific Method: 2) Research

Explore resources that may have information about that question or problem.

• Here, the scientist conducts library research and interacts with other scientists to develop knowledge about the question.

• Example: I know that my neighbor uses fertilizer on her plants and I don’t.

The Scientific Process:

6 Steps to the Scientific Method: 3) Hypothesis

• A possible explanation or answer to the questions.• Example: • Hypothesis -Fertilizer makes plants grow faster.

State Test Question

• What is the starting point of scientific inquiry?

A. Theory development

B. Observation and question formation

C. Experimental design

D. Review of what is already known

State Test Question• Marta wants to conduct a science fair project examining the

effects of ultraviolet light on the growth rate of a certain plant species. She will expose 30 plants to high levels of ultraviolet light and 30 plants to normal levels of ultraviolet light. She will then compare the average growth rates in each group.

• What is the MOST reasonable hypothesis that could best be tested with this experiment?

A. All plant species require ultraviolet light to grow.B. This plant species grows more slowly under high levels of ultraviolet

light.C. Ultraviolet light has no effect on growth in any plants.D. Plants require only small amounts of ultraviolet light to grow normally.

The Scientific Process:

6 Steps to the Scientific Method: 4) Experiment

• A planned procedure to test a hypothesis.• An experiment tests the hypothesis.• A hypothesis tests only one factor (variable) at a

time.

The Scientific Process:6 steps to the scientific Method

4. ExperimentThere is a Control group and one or more variables

The control group is the group getting all the factors except the experimental treatment. The factors are also called constants. Constants are kept the same for all the groups being tested in the experiment.

The experimental groups are the groups getting experimental treatment. The group being tested in the experiment.

The Scientific Process:

6 Steps to the Scientific Method: 4) Experiment

Example: I test to see if fertilizer has an effect on plants.

State Test Question

• A social researcher conducted an experiment to test the effect of sleep deprivation on reaction times. Fifty working adults in an evening study were awakened every 2 hours during an 8-hour period at night and were asked to catch a tennis ball fired from a machine at exactly 20 miles per hour.

• What would be an effective control for this experiment which would provide a basis for meaningful comparisons?

A. The same participants’ reaction times tested in the middle of day

B. Average reaction times at night for the population at largeC. Average reaction times during the day for population at largeD. The same participants after a full 8 hours of sleep deprivation

State Test Question

• Which of these is kept the same for all of the groups being tested in an experiment?

A. Conclusion

B. Constant

C. Hypothesis

D. Variable

State Test Question

• A social researcher conducted an experiment to test the effect of sleep deprivation on reaction times. Fifty working adults in an evening study were awakened every 2 hours during an 8-hour period at night and were asked to catch a tennis ball fired from a machine at exactly 20 miles per hour.

• Which of the following would NOT be an effective added control for the experiment?

A. Participants’ diets are restricted.B. Participants’ sleep patterns are recorded for one month prior

to experiment.C. Wake-up alarms are selected by each participant.D. Population of participants is increased.

State Test Question

• A scientist wanted to test the effect of bright sunlight on cave grasshoppers, which are accustomed to total darkness. During the experiment, what would be the purpose of keeping some grasshoppers in total darkness?

A. They would serve as the control group.

B. They would exhibit the effects of bright sunlight on cave grasshoppers.

C. They would serve as the test group.

D. They would be subjected to later studies.

• Placebo an inert substance given to the control group and should have no effect on the control group.

• The purpose of a placebo is to eliminate biases. Placebos are often given in experiments involving people because the attitudes of people can be a factor in the experiment.

• Ex: A pharmaceutical company may want to test the effects of a blood pressure medication. The experimental group would receive a pill with the medication, but the control group would receive a placebo, a pill that does not contain any medication. The group members would not know ifthey received a pill with the medication or a pill with no medication. People who think they have been given a medication, even if it is a placebo, can sometimes improve a health condition just because they believe that the medicine they receive will help them. This is called the placebo effect.

• Sometimes, the doctors don’t know which participants have the placebo and which have the experimental drug. This keeps the doctors from treating the participants differently. This is called a double-blind study, and it helps to eliminates biases.

State Test Question

• In an experiment to test their new drug on humans, two scientists planned to give volunteers one of two drugs:

• Drug A – experimental drug• Drug B – placebo (sugar pill)

• Which of these would MOST effectively reduce the effect of the bias of the scientists who developed the experimental drug?

A. Introduce a third drug into the experiment.B. Decrease the number of experimenters from two to one.C. Have a third researcher label and distribute the samples.D. Replace a portion of the placebos with aspirin.

The Scientific Process: 6 Steps to the Scientific Method:

Independent—the variable being tested. The variable that changes in the experiment. It is on the X-axis of a graph.

Example: The independent variable would be the fertilizer

Dependent—the variable being measured at the end of the experiment. It is on the Y-axis of a graph. (depends on the independent variable)

Example: The growth of the plants would be the dependent variable.

X-axis; independent variable

Y-axis; dependent variable

State Test Question

• Drug manufacturers must test their new products before they can be marketed. A pill containing a new drug was given to participants in Group A. A pill containing NO drug was given to the same number of participants in Group B. In this test, the drug given to the participants in Group A was the ---

A. conclusion.B. hypothesis.C. dependent variable.D. independent variable.

State Test Question

• Which of these is different for all the groups being tested in an experiment?

A. Hypothesis

B. Constant

C. Control

D. Variable

The Scientific Process:

6 Steps to the Scientific Method: 5) Data

Data from the experiment is collected, recorded, and analyzed.

Example: I record the differences in growth of the plants.

The Scientific Process:

6 Steps to the Scientific Method: 6) Conclusion Example: My experiment showed that plants

with fertilizer grew faster and bigger. *If your hypothesis was correct, problem solved. *If your hypothesis was incorrect, the experiment

failed.

**Don’t give up!! Do more research. Don’t trash your info; build from it!

The Scientific Process:6 Steps to the Scientific Method:

****For a conclusion to be meaningful or valid, the experiment must be repeatable with the same results!!****

Models, such as graphs, can be used to illustrate your conclusions in a visual manner.

The Scientific Process:

Theory—a set of related hypotheses that have been tested and confirmed many times by many scientists.

A theory unites and explains a broad range of observations. It is not the same as the general definition—it does NOT imply a lack of knowledge or a guess.

State Test Question

• A theory can best be defined as –A. an educated guess about an observed

phenomenon.

B. a hypothesis.

C. an idea supported by many experiments and observations.

D. a prediction about an experimental outcome

State Test Question

• Which of the following BEST represents a difference between a hypothesis and a theory?

A. Theories can be used interchangeably with laws.

B. Theories are hypotheses that are supported by repeated experiment.

C. Theories relate to independent variables and hypotheses relate to dependent variables.

D. Theories describe “how” things happen and hypotheses describe “why” things happen.

Scientific Method Cont.

• Hypothesis—an explanation for an observation that can be tested by additional observations or experimentation.

• Prediction—the outcome that is expected if a hypothesis is correct.

• Observation—the act of noting or perceiving objects or events using the senses.

State Test Question• Upon arriving home from school, Ramon finds that

his TV will not turn on. He finds that the TV is plugged in, so he guesses that the batteries in the remote control must need replacing. He replaces the batteries, and the TV turns on. In this very simple example, Ramon has just applied some elements of the scientific method.

• When Ramon assumed the remote control batteries needed replacing, he was

A. making an observation.B. forming a hypothesis.C. conducting an experiment to test a hypothesis.D. using a control group.

Elements of a Good Experiment

Increased Population Size—the more subjects you have the better your experiment will be. It helps to eliminate random errors.

Control group— a predictable group that you “know” what to expect; receives no experimental treatment. Used for comparison with variable group

Experimental group— a group containing the independent variable; compared to the control group. Should be identical to control group with only one thing (the independent variable) different.

State Test Question

• A researcher hypothesizes that a small amount of caffeine has a positive effect on memory. Fifty people were given a small amount of caffeine before take a memorization test. The average test score was 85 percent.

• Which of the following explains why the above experiment is NOT a valid test of the researcher’s hypothesis?

A. The sample size of 50 was too small.B. Caffeine has been shown not to affect memory.C. The average score was not high enough.D. There was no control group

State Test Question

• The result of a scientific experiment is PROBABLY valid if ---

A. most people believe the result is correct.

B. repetitions give consistent data.

C. it is based on a hypothesis.

D. it is done by a world-famous scientist.

State Test Question

• In a controlled experiment, 25 laboratory mice of similar size and age are divided into five groups with five mice each. Four of the groups are given doses of an experimental drug. One group is given a placebo.

• What is the control in this experiment?A. The scientistB. The drugC. The placeboD. The total number of mice

State Test Question

• The difference between an experimental group and a control group is that the ---

A. experimental group has a known outcome.

B. experimental group contains the variable being tested.

C. control group contains no variables being tested.

D. control group is needed only when testing more than one variable.

Elements of a Good Experiment

Independent variable— the ONLY difference between the control group and the variable group. Usually, the independent variable is what you are testing the effect of in your experiment (Factor that is varied)

Dependent variable— the specific result you are looking for to prove your hypothesis. This is usually something you are measuring, the effect of the independent variable. (Factor that is measured)

State Test Question

• The control group in a correctly designed experiment is MOST likely—

A. a smaller size than the experimental group.

B. the same size as the experimental group but receives no experimental treatment.

C. the same size as the experimental group and receives only part of the experimental treatment.

D. a large size than the experimental group.

Dependent Variable

What is measured

Independent Variable

What can change

The Scientific Process:Steps in the Scientific Method

Collecting Observations

Asking Questions

Forming Hypothesis & Making Predictions

Experimenting

Drawing Conclusions

State Test Question

• To do an effective investigation of the damage caused by acid rain in a certain region, all of the following methods should be used EXCEPT—

A. forming a hypothesis as to possible causes of acid rain in the region.

B. conducting pH tests on bodies of water within the region and comparing acidity to normal rain water.

C. investigating weather patterns to locate winds that might sweep pollutants into the region.

D. keeping rainfall and temperature readings throughout the year to measure any increases in thermal heating.

State Test Question

• Which of the following is the proper sequence of events for the scientific method?

A. Experiment → Hypothesis → Conclusion

B. Theory → Hypothesis → Experiment

C. Hypothesis → Experiment → Theory

D. Theory → Conclusion → Hypothesis

State Test Question

• Which of these is TRUE of a proper scientific experiment being conducted under reasonably similar conditions?

A. It should provide identical results.

B. Anyone should be able to repeat it.

C. It should disprove a hypothesis.

D. Anyone should be able to influence the results.

Rules and Guidelines for Graphing:• What is a graph? Graphs provide visual summaries

of data to demonstrate relationships between variables in an experiment. A well-constructed graph usually communicates experimental findings better than a data table. They are constructed to help analyze experimental results and predict future trends in the experiment.

• There are three main types of graphs we will use in this class: Line graph, Bar graph, and Pie chart. Graphs have two axes: the horizontal axis (x-axis) where the independent variable is usually plotted; the vertical axis (y-axis) where the dependent variable is usually plotted.

Y axis (Dependent Variable)

X axis (Independent Variable)

• 1) Line Graph- Used to show continuous data. Ex: height of plants, amount of fertilizer; length in

time. This is

information that

can go on.

• 2) Bar Graph- Used to show data that is categorized or counted. Ex: months of the year, brands of gasoline, number of children, kinds of animal or color. This is information that stops.

• 3) Pie Chart- Used when you want to show percentages. The size of each “slice” is proportional to the percentage of that item, and all the of the “slices” in the pie can be added together to equal 100 percent.

• Diagrams: – These are labeled pictures that show a

relationship between objects or parts. – They are used to communicate data in an

experiment or to give general information about a biology topic.

State Test Question

Kudzu is NOT a native plant to Mississippi. It was imported to control erosion and rapidly became a nuisance. Which type of graph would BEST show the percentage of Mississippi that covered by kudzu?

A. A pie graphB. A bar graphC. A line graphD. A pictograph