Successful Successful Scientific Scientific

InquiryInquiry

1. 1. Ask a question Ask a question – Observe a situation and – Observe a situation and notice that something is happening. Ask a notice that something is happening. Ask a question about what is happening. What will question about what is happening. What will be the purpose of the experiment?be the purpose of the experiment?

2. 2. Collect Prior Knowledge Collect Prior Knowledge - What is - What is already known about the subject? This is the already known about the subject? This is the research/background knowledge portion.research/background knowledge portion.

3. 3. Form a hypothesis Form a hypothesis - If…., then. “If” - If…., then. “If” contains the independent variable, “then” the contains the independent variable, “then” the dependentdependent

variable.variable.

Steps of the Scientific ProcessSteps of the Scientific Process

4. 4. Conduct an experiment Conduct an experiment - Must have only - Must have only one independent variable per experimental one independent variable per experimental group. Record data - whatever is directly group. Record data - whatever is directly measured as the dependent variable.measured as the dependent variable.

5. 5. Analyze data Analyze data - Make graphs, apply math, - Make graphs, apply math, etc.etc.

6. 6. Draw a Conclusion Draw a Conclusion - What is the data - What is the data telling us?telling us?

7. 7. Repeat/Record ResultsRepeat/Record Results

When you start an experiment you need to identify the following first…

1. The question or problem statement.2. The variables:

Independent variable (The ONE that is being changed/tested by the scientist) Dependent variable (The ONE that is being measured) Controlled OR Constant variables (ALL of the things that are kept the same from one group to the next)

3. The control group (The group where NOTHING is changed, used for comparison)4. The hypothesis (An “If, then” statement including variables)

Charlie wants to find out if plants grow Charlie wants to find out if plants grow better with short wavelength light or long better with short wavelength light or long wavelength light. He obtains 30 lima bean wavelength light. He obtains 30 lima bean seedlings, each with two leaves, all planted seedlings, each with two leaves, all planted in 15cm plastic pots in commercial potting in 15cm plastic pots in commercial potting soil. Ten plants are placed under a full soil. Ten plants are placed under a full spectrum grow light, 10 are placed under spectrum grow light, 10 are placed under short wavelength light and 10 are placed short wavelength light and 10 are placed under long wavelength light. All are kept in under long wavelength light. All are kept in the same room and a box is place over each the same room and a box is place over each group. At the end of each week, for six group. At the end of each week, for six weeks, he counts and records the number of weeks, he counts and records the number of leaves on each plant. At the end of the leaves on each plant. At the end of the experiment, the full spectrum plants have an experiment, the full spectrum plants have an average of 27 leaves, the short wavelength average of 27 leaves, the short wavelength plants have an average of 18 leaves and the plants have an average of 18 leaves and the long wavelength plants have an average of long wavelength plants have an average of 12 leaves.12 leaves.

Example…

Example continued…Example continued…

Problem Statement: How do plants react to different wavelengths of light?

Independent Variable: Different wavelengths of light (short and long)

Dependent Variable: Number of leaves on each plant

Controlled/Constant Variables: Lima bean seedlings with two leaves each, all planted in 15cm plastic pots, all plantedin the same type and amount of potting soil, all receive the same amount of water, same length of growth time, etc.

Control Group: The group of plants placed under a full spectrum grow light

Hypothesis: If lima bean plants are placed under a short wavelengthgrow light, then the bean plant will grow more leaves.

Anna wants to test the effect of Anna wants to test the effect of fertilizer on daisy plants. She buys 45 fertilizer on daisy plants. She buys 45 plants of similar height, and separates plants of similar height, and separates them into three groups of 15. Group A them into three groups of 15. Group A receives no fertilizer. Group B receives receives no fertilizer. Group B receives two grams of fertilizer every week. two grams of fertilizer every week. Group C receives four grams of Group C receives four grams of fertilizer every week. All of the plants fertilizer every week. All of the plants receive the same amounts of light and receive the same amounts of light and water. The heights of the plants are water. The heights of the plants are recorded each week for three months. recorded each week for three months. At the end of three months, plants in At the end of three months, plants in Group A average 33cm tall, plants in Group A average 33cm tall, plants in Group B average 37 cm tall, and plants Group B average 37 cm tall, and plants in Group C average 43cm tallin Group C average 43cm tall. .

Your turn to try it…Your turn to try it…

Problem Statement:

Independent Variable:

Dependent Variable:

Controlled/Constant Variables:

Control Group:

Hypothesis:

Help Anna set-up her experiment…

1. Why is it important that the plants are all 1. Why is it important that the plants are all the same type of plants and they are all similar the same type of plants and they are all similar heights when the experiment begins?heights when the experiment begins?

2. A controlled experiment tests ________ 2. A controlled experiment tests ________ independent variable at a time.independent variable at a time.

3. What would be the logical conclusion from 3. What would be the logical conclusion from the results of this experiment?the results of this experiment?

Follow-Up Qs