1. 10-11-17 Types of Scientific Investigations

2. Do Now: Complete in your science notebook
Copy the following questions in your science notebook:
What was the person trying to study?
How did that person try to study that topic?
Was this method an experiment? Why or why not?
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3. Types of Scientific Investigations
Standard SC.7.N.1.3 – Distinguish between an experiment (which must involve the identification and control of variables) and other forms of scientific investigation and explain that not all scientific knowledge is derived from experimentation.
Lesson Objective: I can identify methods that scientists use to gain scientific knowledge

4. Look at the following 3 investigations. How are they alike
Look at the following 3 investigations. How are they alike? How are they different?
Investigation 1
Investigation 2
Investigation 3
A student used a microscope to observe an amoeba to determine how the organism moved.
A student used a hand lens to examine the color and texture of four different rocks.
A student planted rye grass seeds in potting soil in three plastic cups, placing them on a window sill, and watering one daily, one every third day, and one not at all.

5. 3 Types of Investigations
Scientists use 3 types of investigations to research and develop explanations for events in nature:
Observational Studies
Comparative Studies
Controlled Experiments

6. Observational Studies
An investigation in which scientific questions are investigated and observations of phenomena are recorded and catalogued.
A scientist will observe and measure variables without controlling them in any way
The scientist looks for patterns in their data in order to make inferences.
Purpose: Draw conclusions
Investigation 1 about the amoeba is an example of an observational study.

7. Observational Studies (cont.)
Can include both quantitative and/or qualitative data.
Can be identified with the following key words:
Includes the following parts of scientific inquiry:
Observe
Describe
List
Observations and asking questions
Identify
Procedure
Analyzing data
Drawing conclusions
Does not include hypothesis or predictions

8. Comparative Studies
An investigation where observations are made that compare two objects or phenomena
A scientist will collect data about two or more subjects, identifying ways in which they compare or differ.
This could be collecting data on different organisms/objects/features, or collecting data under different conditions (e.g., times of year, temperatures, locations)
Purpose: to determine relationships
Investigation 2 about the rocks is an example of a comparative study.

9. Comparative studies (cont.)
Involves looking for patterns or trends by comparing similarities and differences over time and under various circumstances
Analyzing data
Drawing conclusions
Does not include a control group
Can be identified with the following key words:
Includes the following parts of scientific inquiry
Compare/contrast
Observations and Asking Questions
Similarity/difference
Hypothesis
Categorize
Prediction
Testing the hypothesis with independent and dependent variables.

10. Controlled Experiments
An organized scientific investigation that includes a control group and is designed to test a hypothesis
A scientist is testing the effect of one factor on another factor by changing only the factor they are testing and keeping everything else the same.
Independent variable: the factor that is being changed
Dependent variable: the factor that is being effected
Purpose: to determine causal relationships
Investigation 3 about the seeds is an example of a controlled experiment.

11. Controlled Experiments (cont.)
Involves determining how a variable affects a control and experimental group.
Testing the hypothesis (independent and dependent variables, control and experimental group)
Analyzing data
Drawing conclusions
Includes the following parts of scientific inquiry:
Can be identified with the following key words:
Observations and Asking Questions
Control and experimental groups
Hypothesis
Constants
Prediction
Testing the effects of…

12. Think-Pair-Share: Copy the chart below
Think-Pair-Share: Copy the chart below. In groups of 3, assign an investigation type to each person. That person is responsible for completing the row for the particular investigation. After 3 minutes, rejoin group and share your answers.
Investigation Type
Purpose
Includes a Hypothesis?
Has variables (independent and dependent)?
Has a control and experimental group?
Observational
Comparative
Experimental

13. Think-Pair-Share: Copy the chart below
Think-Pair-Share: Copy the chart below. In groups of 3, assign an investigation type to each person. That person is responsible for completing the row for the particular investigation. After 3 minutes, rejoin group and share your answers.
Investigation Type
Purpose
Includes a Hypothesis?
Has variables (independent and dependent)?
Has a control and experimental group?
Observational
To draw conclusions
No, but does answer a question No
Comparative
To determine relationships
Yes
Experimental
To determine a causal relationship