Title: Scientific Reasoning - Planning Comparative and Experimental Investigations | Texas Gateway
Headings: Scientific Reasoning - Planning Comparative and Experimental Investigations
Scientific Reasoning - Planning Comparative and Experimental Investigations
Comparative Vs. Experimental Investigations
Variables (Independent and Dependent) and Group (Control and Experimental)
Formulating Hypothesis
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Content: descriptive, comparative, and experimental. In this resource we will focus on comparative and experimental investigations. Comparative investigations involve collecting data on different organisms/objects/features, or collecting data under different conditions (e.g., times of year, temperatures, locations) to make a comparison. In comparative investigations scientists look for patterns or trends by comparing similarities and differences over time and under various circumstances. Identifying the boiling points of three different liquids and using a hand lens to observe the external anatomy of two different insects are examples of comparative investigations. Experimental investigations involve a process in which a "fair test" is designed and variables are actively manipulated, controlled, and measured in an effort to gather evidence to support or refute a causal relationship. Experimental investigations have a control group which does not receive any treatment. For example, a student might conduct an investigation to answer the question "What is the effect of light color on plant growth?" In this experiment, the variable color of light is changed by the student. The student may compare red light to green light to natural light.