Big Ideas 1 and 2The Practice of Science and the Characteristicsof Scientific Knowledge

Florida Next Generation Sunshine State Standards:

SC.5.N.1.1 –Define a problem, use appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types such as: systematic observations, experiments requiring the identification of variables, collecting and organizing data, interpreting data in charts, tables and graphics, analyze information, make predictions and defend conclusions.

SC.5.N.2.1 –Recognize and explain that science is grounded in empirical observations that are testable; explanation must always be linked with evidence.

SC.5.N.2.2 –Recognize and explain that when scientific investigations are carried out, the evidence produced by those investigations should be replicable by others.

Terms

English

Spanish

Haitian Creole

1. constant

constante

konstan(ki pa chanje)

2. control group

grupo de control

group ki kontwole

3. data table

tabla de datos

tab enfòmasyon

4. experiment

experimento

eksperyans

5. inference

deducción

dediksyon

6. inquiry

investigación/averiguación

anket

7. investigation

investigación

envestigasyon

8. model

modelo

modèl

9. repeated trials

la repetición de pruebas

repete esè

10. observation

observación

obsèvasyon

11. prediction

predicción

prediksyon

12. variable

variable

varyab

outcome variable

variable de resultado

varyab rezilta

test variable

prueba variable

varyab tès

Does This Matter to Me?

Science is different from other subjects in school like language arts and social studies because it focuses on studying the natural world by gathering evidence through observations. These observations form the basis of all study of science. That means you always have with you the basic tools of science – your eyes, ears, nose, skin, and tongue. You do basic science every day when you notice if it is rainy or sunny and then use this observation to decide whether or not to wear a jacket. You need to know science so that you can make good decisions in life, such as what cars to buy, what foods to eat, how to take care of your pets, and lots more things.

Scientists are people who learn to use special methods to make sure observations provide information that others can use. Some scientists work in laboratories, while others use science in their work, such as doctors, nurses, engineers, and pilots. You may decide to become a scientist, or a person who uses science in your work.

Talk in your group about these questions:

· Do you know people who use science in their work?

· Who are they and what do they do?

The Nature of Science

(SC.5.N.1.1, SC.5.N.2.1, SC.5.N.2.2)

In science, observations provide evidence as information. This information validates explanations of the natural world.

There are various methods that scientists follow to do their work. While scientists don’t all work the same way, all scientists are known to question things, discuss their findings with others, and check each others’ evidence and explanations to see if they get similar results.

Science inquiry is one method scientists use to learn about the natural world. When you conduct science inquiry, you are learning to think and act in one way of doing science.

In this unit, you will practice doing science inquiry as you:

· ask questions,

· make plans to answer the questions,

· carry out the plans,

· find your answers,

· report your findings,

· share your findings with your peers,

· ask further questions, and

· apply what you have learned.

Observation

Observations are important when doing science inquiry. When you make observations during a science experiment, you are gathering data or information about your experiment. Observations involve using your five senses (hearing, sight, touch, smell, and taste) to understand the world around you. Because you make observations using your five senses, if you and a friend are making an observation of the same things, your observations should be similar. For example, when using the sense of touch, you both could describe a rock as rough or bumpy. You might also make an observation that something you taste is sweet or sugary.

The data you gather and record when observing is either quantitative or qualitative. Quantitative observations measure in numbers what you observe, while qualitative observations describe in words what you observe. For example, if you investigate the rate of plant growth over a three-week period, a quantitative observation would be that the plant grew 3 inches. A qualitative observation could be that the plant is wilting and small, with brown and yellow leaves.

Now you try it. Make a quantitative observation

about the picture.

______________________________________

______________________________________

______________________________________

Make a qualitative observation about the

picture.

______________________________________

______________________________________

______________________________________Inference

Just as observations are important in science, so are inferences. An inference is an explanation that uses observations to draw conclusions. When you make an inference, you are giving meaning to your observations. Think about the plant example used earlier. After three weeks, the plant is only 3 inches tall and has brown and yellow leaves. In contrast, the plants growing in your neighbor’s yard are tall and the leaves are green. As you think about your observation, you infer that your plant may not grow very tall or that it may die.

An observation is what you sense and measure. An inference is what you think. If two people observe the same thing, their observations will be similar. This is not the case for inferences. While inferences use observations to draw conclusions, inferences also include your prior knowledge or experiences. For example, if you have never observed a plant growing around your house, you may not infer that small, wilting plants with discolored leaves will probably die.

Make an inference based on the picture.

______________________________________

______________________________________

______________________________________

______________________________________

Prediction

While getting dressed for school in the morning, you may have heard the meteorologist say on the news, “It’s probably going to be a rainy week, so grab your umbrella.” The meteorologist is making a prediction about what the week’s weather will be. Based on what the meteorologist knows about the weather patterns in your area, she makes a prediction about what the weather will be like for the week.

Predictions are statements that forecast what might happen in the future. In science, you make a prediction and then conduct an experiment or make an observation to see if your prediction is accurate. You make predictions based on patterns observed (for example, when you see dark clouds it is likely to rain) or from previous experiences. These observations and experiences help you make more accurate conclusions.

While making accurate predictions is important, it is also important that the reasoning behind the predictions makes sense. If the meteorologist predicts that it is going to rain during the week based on the number of dark-colored cars on the road, does the reasoning behind her prediction make sense?

Imagine you help your mother unload groceries from the car. She gives you the carton of eggs to carry into the house. While swinging the grocery bag containing the eggs, you drop the bag on the floor.

Predict what you will see when you look in the bag (what happened to the eggs).

______________________________________________________________________

______________________________________________________________________

What is the reasoning behind your prediction?

______________________________________________________________________

______________________________________________________________________

Experiments

One way scientists seek to understand and explain the natural world is by conducting science experiments. Experiments involve posing questions, planning investigations, making observations, using tools to collect and analyze data, drawing conclusions, communicating results, exploring further questions, and applying the knowledge in new situations. When you conduct experiments, you are engaging in many of the same activities and thinking processes as scientists in laboratories.

Free Exploration

Some scientists use free exploration to understand and explain the natural world. They gather observations that offer evidence about what they are studying in the field. For example, field biologists study animals in their native habitats, astronomers explore space, and field geologists investigate caves and mountain faulting.

Models

Creating models is another way scientists understand and explain the world around them. This type of science investigation involves recreating a science phenomenon to examine what or how something happens. Scientists often create models when what they want to investigate is too far away, too small to see, or too dangerous to explore. For example, scientists often create models of space because it is too vast to investigate directly. Another example is scientists creating models of volcanoes. Although scientists have explored active volcanoes around the world, doing so is very dangerous. Therefore, scientists make models of volcanoes to better understand volcanic eruptions.

Compare and contrast a model and an experiment.

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Nature of Science Activity: Observation Walk

In this activity, you will use free exploration to learn about observing and recording in science. You will also compare your observations with those of your classmates.

Materials:

· pencil

· index card

Procedures:

1.Think about what you have just learned about science and observations. Observations come from our senses.

a.Close your eyes for a moment and really focus on what you are hearing.

b.Close your eyes again and observe what you feel around you. Do things seem different with your eyes closed?

c.Close your eyes a third time and focus on observing what you smell.

You have closed your eyes a few times to focus on other senses because you are used to seeing as the most common way of observing. It is so natural to think that observing means seeing that we tend to forget to use other senses. In this activity, in addition to seeing, you are going to listen, touch, and smell carefully. We don’t usually taste in science class because it can be dangerous.

2.While you are observing carefully with your senses, as scientists do, it is important that you also record your observations. Use the index card to write down your observations or data: the things you see, hear, feel, and smell.

3.Go on a slow walk for 15 minutes with your class. During this time, do not talk to your friends or teacher. Instead, pay close attention to the things around you while you record your observations on your index card.

4.When you return to class, join your group and share your observations with them. Listen politely to what others observed. You can write down others’ observations.

5.Did you observe anything new on this walk because you were observing more closely? If so, what?

________________________________________________________________________________________________________________________________________________________________________________________________

6.Did the other people in your group have any observations that were different from yours? If so, why do you think that happened?

________________________________________________________________________________________________________________________________________________________________________________________________

7.Did you gather qualitative data, quantitative data, or both? Please circle your answer.

When scientists gather information through free exploration, they check with their peers to compare methods and results. When you shared your observations with your classmates, you were doing this same type of scientific activity. By comparing your observations and talking about them, you could get your classmates’ ideas about your observations and gain more information. This helps to check and verify your observations.

Inquiry Framework

While there are different ways to engage in science, you will be conducting experiments or science inquiry by using the inquiry framework. Although science does not always follow a step-by-step process like the inquiry framework, it always includes observations and data as evidence. You can follow these steps to guide you, as you conduct experiments or other types of investigations in your science class.

Inquiry Framework

1. Questioning

State the problem

· What do I want to find out? (Write in the form of a question.)

Make a prediction

· What do I think will happen? (Explain your reasoning.)

2. Planning

Read the materials and procedures

· Do I have all of the necessary materials?

· Have I read the procedures?

· Summarize the procedures in your own words.

3. Implementing

Gather the materials

· What materials do I need to implement my plan?

Follow the procedures

· What steps do I need to take to implement my plan?

Observe and record the results

· What happens after I implement my plan?

· What do I observe?

· How do I display my results? (a graph, chart, table)

4. Concluding

Draw a conclusion

· What did I find out?

· Was my prediction supported or not?

(Remember: It is okay if the prediction is not supported.)

· What was my evidence?

5. Reporting

Share my results (informal)

· What do I want to tell others about the activity?

Produce a report (formal)

· How do I answer the problem statement and related questions?

6. Inquiry Extension

Reflect on your results

· If I did this activity again, how would I improve it?

· What would be a good follow-up experiment based on what I learned?

7. Application

Make connections

· How does this activity relate to what happens in the real world?

· How could I apply the results in new situations?

Doing Good Science Inquiry

(SC.5.N.1.3, SC.5.N.2.1, SC.5.N.2.2)

While you are using the inquiry framework as a guide, it is important to follow good science inquiry by determining the variables in an experiment, making accurate measurements, and conducting your experiment more than one time.

First, when you conduct an experiment, you usually work with variables. A variable is something that you change in an experiment. To make sure that results in an experiment are valid, you should change only one variable at a time. The variable you are testing is called the test variable (independent variable), and the variable you are measuring is called the outcome variable (dependent variable). A constant is a variable that you keep the same throughout the experiment. You may have several constants in one experiment.

In some experiments, a control group is used to see the effect of the test variable on the outcome variable. For example, you are testing how tall a plant will grow (outcome variable) when it is given 10 ml of fertilizer (test variable). You have 20 plants – 10 plants treated with 10 ml fertilizer (test group) and 10 plants without fertilizer (control group). Sun, water, location, and temperature are kept constant for both groups. When the data are collected, you will know with more certainty that any change is due to the variable you are testing, the fertilizer.

Second, scientists try to be as accurate as possible when taking their measurements. As you conduct your experiments, you need to make sure that your measurements are accurate. Your results should be repeatable so that you can draw accurate conclusions from your data.

Finally, when doing science inquiry, you need to conduct your experiment more than one time. If you conduct the experiment only one time, you cannot be sure that your results are correct. You need to do repeated trials of your experiment so that you can validate your data. In the plant fertilizer experiment, the experiment was repeated 10 times by growing 10 plants in each group. This is one way of conducting repeated trials.

How might you record the data you collect in an experiment? Scientists use data tables to keep track of the information they gather. We will use different types of data tables throughout this book.

In Inquiry 1 below, you will start learning how to use the inquiry framework.

Inquiry 1: Warming Sand and Water

(SC.5.N.1.1)

Inquiry Framework

1. Questioning

State the problem

If you warm the same amount of sand and water in the Sun for 20 minutes, will the temperature change be the same?

Make a prediction

|_|The sand will warm more than the water.

|_|The water will warm more than the sand.

|_|The water and the sand will warm the same amount.

2.Planning

Read the materials and procedures

· Do I have all of the necessary materials?

|_|Yes|_|No

· Have I read the procedures?

|_|Yes|_|No

· Summarize the procedures in your own words.

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

___________________________________________________

3. Implementing

Gather the materials

|_|1 graduated cylinder

|_|1 small bag of sand at room temperature

|_|water at room temperature

|_|2 thermometers

|_| 2 plastic cups

Follow the procedures

1. |_| Use the graduated cylinder to measure 50 ml of sand at room temperature. Pour it into one plastic cup.

2. |_| Use the graduated cylinder to measure 50 ml of water at room temperature. Pour it into the other plastic cup.

3. |_| Using a thermometer, measure the temperature of the sand and record this measurement in the Data Table.

4. |_| Using a thermometer, measure the temperature of the water and record this measurement in the Data Table.

5. |_| Place both cups in the Sun at the same time for 20 minutes.

6. |_| Remove the cups from the Sun at the same time after 20 minutes.

7. |_| Subtract the Start Temperature from the End Temperature for water and for sand. Put these numbers in the Data Table under Temperature Difference.

Start Temperature

(Degrees Celsius)

End Temperature

(Degrees Celsius)

Temperature Difference

(Degrees Celsius)

50 ml Sand

50 ml Water

Observe and record the results

Data Table: Temperatures of Water and Sand

4. Concluding

Draw a conclusion

What did you find out? Check the correct conclusion:

|_|Water was warmed more than sand.

|_|Sand was warmed more than water.

|_|Water and sand were warmed the same amount.

Compare what you thought would happen with what actually happened. Did the results support your prediction?

|_|Yes|_|No

5. Reporting

Share your results

What do you want to tell others about the activity?

Talk with your group members about what you did and what you observed.

Produce a report

Record what you did so others can learn. Write the answers to the following questions:

1. When you warmed the same amount of sand and water in the Sun for the same amount of time, what did you find about the temperature?

_________________________________________________________________________________________________________________________________________________________

2. What do you predict will happen if you put the cups in the freezer?

_________________________________________________________________________________________________________________________________________________________

6. Inquiry

Extension

Reflect on your results

· If I did this activity again, how would I improve it?

· What would be a good follow-up experiment based on what

I learned?

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

7. Application

Make connections

· How does this activity relate to what happens in the real world?

· How could I apply the results in new situations?

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

In this activity, you learned that when placed in the Sun for equal amounts of time, water and sand do not warm the same amount. Sand warms more than water, or sand warms more quickly than water.

What did you measure in the activity? ______________________________________

What tool(s) did you use to measure? ______________________________________

What unit(s) did you use to measure? ______________________________________

Data Tables

In Inquiry 1 above, we used a data table. Data tables are used to store and organize information collected during an investigation. In most cases, the test variable (independent variable) appears in the left column. In our experiment, we tested the materials of sand and water. If appropriate, the units of measurement are included in parentheses with the test variable. Since we wanted to find out about temperature, that was our outcome (dependent) variable. The outcome variable is shown across the top of the table with its unit of measurement. Our constants were length of time, amount of the materials, and location for data collection.

Reading a Data Table

The Effect of the Type of Bird Feed on the Number of Birds

Type of Bird Feed

Number of Birds

Average Number of Birds

Day 1

Day 2

Day 3

Day 4

Day 5

Millet

10

15

17

18

15

15

Milo

2

4

5

5

4

4

Cracked Corn

3

6

8

7

6

6

Safflower

15

10

13

11

11

12

Sunflower

26

28

26

22

28

26

Using the data table, answer the following questions.

1. Which type of bird feed was the most popular choice? ________________________

2. Which type of bird feed was the least popular choice? ________________________

3. Which three types of bird feed would you combine to attract the most birds?

___________________________________________________________________

4. For how many days was the data collected? _______________________________

5. What was the test variable in this investigation? (Remember that the test variable is something that the investigator changes.)

___________________________________________________________________

6. What was the outcome variable in this investigation? (Remember that the outcome variable is something that the investigator measures.)

___________________________________________________________________

7. What were some variables that should have been held constant (for example, location in the yard, time of day that the bird feed was put out, or anything else that might have affected the outcome)?

___________________________________________________________________

___________________________________________________________________

8. What is the title of the data table? ________________________________________

___________________________________________________________________

Making a Data Table

The data were collected using an electromagnet that was made using a battery, a switch, a piece of insulated wire, and a nail. The investigator used the electromagnet to pick up paperclips. She conducted three trials for each number of coils.

Number of Coils

Number of Paper Clips in Each Trial

5

3, 5, 4

10

7, 8, 6

15

11, 10, 12

20

15, 13, 14

Complete the data table below by filling in the missing information.

The Effect of _____________________ on _________________________

Number of Coils

_____________________________

Average Number of Paperclips

Trial 1

___________

Trial 3

5

10

The Practice of Science

You just learned that making observations is a key activity of science. During a science experiment, information is gathered about the experiment to help us understand what is happening. Observations involve using the five senses to understand the world. Therefore, observations made by different people should be similar. Science involves more than just following step-by-step procedures.

Science also involves making inferences when conducting science experiments. Inferences are what you think about observations. When you make an inference, you give meaning to your observations based on your prior knowledge or experiences.

Making predictions is also important when doing science experiments. Predictions are statements that forecast what would happen in the future. You make a prediction and then conduct an experiment or make an observation to see if your prediction is accurate. When making predictions, it is important that the reasoning behind the predictions makes sense.

To understand the natural world better, you can conduct science investigations. One type of science investigation is an experiment or science inquiry. When you use experiments or science inquiry, you are engaging in many of the same activities and thinking processes as scientists in laboratories.

Another type of science investigation is free exploration. When you are exploring you use skills of observing and recording information to understand the world around you. When you investigate using free exploration, you are using methods that field scientists use.

Developing models is another type of science investigation. Models recreate a phenomenon to examine what or how something happens. You create models when what you investigate is too far away, like other planets, or too dangerous to explore, like chemicals. Examples of scientists who use models are astronomers and chemists.

There are different ways to conduct science investigations. In this book, you will be conducting experiments or science inquiry by using the inquiry framework. First, science inquiry involves identifying and testing variables. Variables are things that can change in an experiment. You change one test variable at a time, choose one outcome variable to measure, and keep all other variables constant. Second, you need to make sure that your measurements are accurate. Finally, you need to do repeated trials of your experiment so that you can trust your results.

Assessment

1. Chris wanted to find out what would make his tomato plants grow best. He set up an experiment to find out and planted three little plants. He gave each plant different amounts of water, fertilizer, and sunlight. The amounts are shown below.

Amounts per day

Plant Necessity

Plant 1

Plant 2

Plant 3

Water

10 ml

15 ml

20 ml

Fertilizer

2 grams

5 grams

10 grams

Sunlight

3 hours

6 hours

4 hours

What is the major error with the way Chris ran his experiment? What should he have done to get better results?

______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. Mr. Brown wonders how minerals affect animal growth and decides to conduct an experiment with his chickens. He begins with 3 buckets containing exactly the same amount of chicken feed and then adds the same amount of 2 different minerals to two of the buckets. He adds calcium to one bucket, adds magnesium to another bucket, and doesn’t add any minerals to the third bucket. What scientific term is used to describe the mineral placed in each bucket?

a. Controlb. Hypothesisc. Outcome variable (dependent variable)d. Test variable (independent variable)

3.

Equal masses of paper towel were used to soak up water from a cup. Which question can be answered from the information above?

a. Which paper towel is the best buy?

b. Which paper towel is most absorbent?

c. Which paper towel is the most colorful?

d. Which paper towel is safest for the environment?

4.

The table indicates the amount of time that four different brands of batteries worked in a flashlight. Which of the following statements is supported by this information?

a. Brand L caused the light to shine farther than the other brands tested.

b. Brand M lasted longer than the other brands tested.

c. Brand N gave off a stronger light than the other brands tested.

d. Brand O was more expensive than the other brands tested.

5. Alejandro wants to find out whether mealworms prefer apples or pears. He places an apple slice at one end of a cardboard box and a pear slice at the other end. He then places 20 mealworms in the center of the box, about 15 centimeters (cm) from each piece of fruit. After several hours, he counts the mealworms on or under the apple, the mealworms on or under the pear, and the mealworms not touching either the apple or the pear. Alejandro repeated his experiment four times. The data are recorded in the table shown below.

Which of the following is the best conclusion that Alejandro can make from this data?

a. Mealworms prefer pears.

b. Mealworms prefer apples.

c. Mealworms do not prefer apples or pears.

d. Mealworms do not go near apples or pears.

Big Ideas 1 and 2 4