10-11-17 Types of Scientific Investigations

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? http://www.cpalms.org/Public/PreviewResourcePerspectivesVideo/Pre view/128384

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

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.

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

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.

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

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.

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.

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.

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…

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

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