Thinking like a Scientist The Scientific Inquiry/Process And The Scientific Method

What is Science? Science includes knowledge of the physical universe and the ways our knowledge is acquired. Science is a method of finding things out.

The Scientific Inquiry/Process There are two parts to the Scientific Inquiry/Process: 1. Observations 2. Inferences 2a. Predictions

Observations Observing is using one or more of your senses, (sight, hearing, smell, taste, or touch), to gather information about the world. Example: seeing the black chalkboard, smelling lunch cooking, tasting a sour lemon, hearing my voice, and feeling the smooth desk top.

Observations Observations can be either qualitative or quantitative. Qualitative observations are descriptions that do not use numbers: colors, smells, texture, sounds. (quality) The classroom walls are yellow. Quantitative observations are descriptions that use numbers: counting objects, measurements, etc. (quantity) There are 21 students in the room.

Inferring Making an inference, or inferring, is explaining or interpreting an observation or statement. Example: Observation: The sky is cloudy and gray today. Inference: It probably is going to rain today.

Inference Base your inference on accurate qualitative or quantitative observations. Use prior knowledge and recent observations when making an inference.

Predicting Predicting is making an inference about a future event based on current evidence or past experience. One way to make a prediction is to look for a pattern. In science, predictions are usually tested. When you make a prediction in science, try to make it as specific as you can, don’t just guess.

The Scientific Method There are basically six major parts to the scientific method. Problem or question Optional (Background information) 2. Hypothesis Design/Perform Experiment Collect/Interpret Data Conclusion Communication Optional (Additional comments or additional questions to further test).

Posing a Question Scientists design experiments to answer questions or solve problems. Does adding sugar to the water in a vase of flowers keep the flowers fresh? How do people get colds?

Hypothesis A hypothesis is a possible explanation for a set of observations or answer to a scientific question. Hypotheses are based on a person’s observations and previous knowledge or experience. A hypothesis, in science, must be testable.

Designing and Performing an Experiment There are three parts to designing and performing an experiment: Variables and Operational Definitions Materials Procedures

Variables Every experiment involves several variables, or factors that can change. For example: Will houseplants grow faster if you make the room warmer? To answer this question, you decide to grow plants at different temperatures. The variable that you purposely change, temperature, is the manipulated variable or independent variable. The factor that may change as a result of the manipulated variable, how fast the plants grow, is the responding variable or dependent variable.

Variables You try: You are planning an experiment to find out whether the rate at which water freezes depends on the shape of its container. What is the independent variable? What is the dependent variable?

Variables Controlling variables are very important. Controlling variables means keeping all conditions the same except for the manipulated variable. In the experiment on temperature and plant growth, you have to control other variables that might also affect growth rate: such as using identical plants – both being ferns, equal amount of soil, same amount of water, etc.

Variables Name some controlling variables for the following: You are planning an experiment to find out whether the rate at which water freezes depends on the shape of its container.

Operational Definitions An operational definition is a statement that describes how a particular variable is to be measured, or how an object or condition is to be recognized. Example: Lemon juice, vinegar, and certain other substances are acids. To find out whether a substance is an acid, place a drop of the substance on blue litmus paper. Operational Definition: Substances that cause the litmus paper to turn pink are acids.

Operational Definitions Write an operational definition for each underlined idea: On a cold day, let the water in the pan freeze outdoors. You will test these two fertilizers to determine which one helps plants grow faster.

Operational Definitions Give an operational definition for the following: You are planning an experiment to find out whether the rate at which water freezes depends on the shape of its container.

Review - Variables: You are planning an experiment to find out whether the rate at which water freezes depends on the shape of its container. Independent Variable: Dependent Variable: Controlling variables: Operational Definition:

Materials Before you carrying out your procedures, you need to list your materials. Include measurements, such as 1 liter of water, or 2cm by 3cm of a sheet of paper. Materials should be listed to the exact quantity. When writing and performing your procedures, go back and modify materials if needed.

Procedures The procedure describes what you plan to do and identifies the data you plan to collect. The procedure is a step-by-step description of how you will change the manipulated variable and observe the effects upon the responding variable.

Collecting/Interpreting Data During an experiment, you collect data. Data may include measurements, color change observations, journaling observations, etc. After you collect data, you need to interpret what the data means. You can interpret data by making tables, charts, graphs, calculations (averages), or reviewing journal comments. When interpreting data, look for patterns or trends in data information!

Conclusions Drawing a conclusion means making a statement summing up what you have learned from an experiment. When asked to make a conclusion after an experiment, do not state, “this experiment was fun”. This is not a scientific statement. Your conclusion is usually related to your hypothesis. Determine whether your experiment supports your hypothesis or not. If your experiment did not support your hypothesis, try to determine why.

Communication Scientists communicate using written or printed word, such as Published Journals (Educational Psychology Journal) or lab reports. Lab Reports contain the following sections: 1. Problem/Question * Optional: Background information/research 2. Hypothesis 3. Design/Perform Experiment a. Variables and operational definitions b. Materials c. Procedures 4. Data Collection/Data interpretation 5. Conclusion * Optional: Additional research questions or comments.

Scientific Theories Why is testing a scientific question over and over again important? A scientific theory is a well tested scientific concept that explains a wide range of observations. An accepted theory has gone through repeated testing and basically provided the same results.

Scientific Laws Scientific Law: This is a statement of fact meant to explain, in concise terms, an action or set of actions. It is generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They don’t really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true. Some scientific laws, or laws of nature, include the law of gravity, the law of thermodynamics, and Hook’s law of elasticity.