Scientific Inquiry & Experimental Design How do we solve problems in science?

The scientific method… State the problem Form a hypothesis Procedure Results Conclusion Let’s have a more in depth look at what scientist actually use and more scientific terminology.

Experimental Design vs. Scientific Method Research Question Formulating Hypothesis Careful Observation Data Gathering Analysis of Data Identifying patterns in the data State the problem Form a hypothesis Procedure Results Conclusion

Types of Experimental Design Different research questions require different experimental designs. Descriptive Investigations Comparative Investigations Experimental Research Design

Descriptive Investigations An investigation used to explore questions in environmental conditions you cannot control. Ex. Jane Goodall’s study of chimpanzees. Picture hyperlinked to: www.janegoodall.org/media/videos A hypothesis is not required in these investigations.

Comparative Investigations Involves collecting data on different organisms/objects/features, or collecting data under different conditions to make a comparison. Example: times of year, temperatures, locations Hypothesis: Pecan trees produce more pecans during the rainy season than they do during a drought.

Experimental Research Design Can be used when focused on a single variable. Conditions can be controlled. Determines the cause of a problem. Ex.: Thumb Wars

Experimental Research Design: Thumb Wars Research Question Hypothesis Gathering Data Data Analysis Patterns in the data One variable tested: thumb length

Experimental Research Design Research Question: Do plants grow better in coke or water?

Do plants grow better in coke or water? (cont.) Analysis of Data : Using graphs/tables to find trends in the data.

Independent Variable – A variable that you can directly change, or have control over. (What the scientist is changing) What is tested by the scientist What is changed by the scientist Also known as manipulated variables

•The effect caused by the independent variable. •The data   Dependent Variable – The factor, or outcome that will be measured in the experiment. •What is observed •What is measured •The effect caused by the independent variable. •The data •Also called responding variables

  Control Group – the group in the experiment that is not given the treatment the other groups receive. •The group that is under “normal conditions” •Kept “normal” so scientist can see what would happen without the treatment.

   Constants – things that are intentionally kept the same for each specimen in the experiment. •Things that could change but don’t •Kept constant (the same) by scientists •These allow for a fair test.

Do plants grow better in coke or water? Research Question: Do plants grow better in coke or water? Hypothesis Ex: Plants will grow better in water because plants need water to live. Gathering Data: Controlled experiment with one independent variable. Independent Variable: Type of liquid given to plants Dependent Variable: Measured growth of each plant Constants: Conditions kept the same (such as amount of liquid, type of plant, soil, amount of sunlight)