Nature of Science and ExperimentationPresentation Transcript
Dictionary Definition Better Definition
• Whether Pure or Applied, good Science relies heavily on the ability to: – Design valid experiments and make good observations Inquiry/Experimentation Making Observations
• Dictionaries describe science as the observation, identification, description, experimental investigation (scientific method), and theoretical explanation of phenomena.• This is a good description for fields like chemistry and physics where specific experiments can be run but what about other fields like archaeology, or geology where it is not so straightforward? Are these examples of science?
• Science – A way of learning about the natural world through observations and logical reasoning, and allows for growth and change as new ideas are explored. – Though simple, this definition is all encompassing – Within this we can separate out 2 distinct forms of science: Pure Science Applied Science
• Pure Science – Pure science is an aspect of the field that deals directly with research simply for the sake of research. – Experiments are developed and hypothesis’ are tested with the sole purpose of finding out what happens. It is the search for new information or the discovery of a new fact. – Motivated by curiosity – Can basically be thought of as the “search for new information”
• Applied Science (technology) – This is the aspect that involves actually using science, what was discovered using pure science, to improve the technology around us and to improve and ease everyday life.
• A large part of being a good scientist is observation. When we observe there are two types of observations that we can make: – Qualitative – These observations consist only of words. Describe things such as the color, shape, or odor of an object. • Practice Making Qualitative Observations – Quantitative – These observations use actual numbers. They describe aspects of an object that can be measured. Examples would be mass, length, speed, etc. • Practice Making Qualitative Observations Questions
Make 3 Qualitative Observations 1. The product is blue Click for answer 2. The reactants are red and yellow Click for answer 3. A gas was produced during the reaction Click for answer
Make 3 Quantitative Observations 1. There for answerof Click are 94 mL 2. The product has a mass of 112 g Click for answer reactant 3. 12 mL of reactants were changed into a gas Click for answer
Scientific InquiryThe practice of pure science is often referred to asscientific inquiryIn scientific inquiry, an unknown question ispresented, an idea (hypothesis) issuggested as a solution, the possiblesolution is tested (experimentation),and then a conclusion is drawn.This process of inquiry is best described through what isknown as the scientific method
Scientific MethodThe scientific method consists of eight (8) steps:• State the question (what am I trying to find out?)• Collect information (what do we already know?)• Form a hypothesis (what do you think will happen?)• Test your hypothesis (perform the experiment)• Observe your results (ongoing during the experiment)• Record the data (ongoing during the experiment)• Analyze the data• Form a conclusion (either supporting or disproving your hypothesis)
ExperimentationOther than forming a hypothesis, the most important partof the scientific method is the experiment.An experiment is an organized procedure for testing ahypothesisIn order for an experiment to be scientifically valid, it musthave two important parts: 1) A valid experimental setup 2) Valid experimental subjects
Valid Experimental SubjectsIn any experiment, you also must have something to compare the results with, therefore you must have two different types of experimental subjects:• Test Group – this is the subject where you change one variable to see what effect it will have• Control Group – this is used as a standard for comparison. In the control group, no variables get changed
Valid Experimental Setup In any good experiment, you need to be very careful of what you are testing and what you are doing to affect your results. Therefore, you must be careful to only have:• Independent (manipulated) variable – what factor in an experiment that you change. There can only be ONE independent variable in any experiment.• Dependent (responding) variable – what factor in an experiment you are measuring the change as a result of changing the independent variable. The amount of change in the dependent variable is your “results”• Constants – all of the other factors in the experiment which must remain unchanged
Example: A student wants to see how watering a plant with salt water affects its growth. He has twenty plants. The first five he waters with regular water, the second five he uses water with 5 tablespoons of salt, the third five he uses water with 10 tablespoons of salt, and the last 5 he uses water with 15 tablespoons of salt. The first group of plants grows to an average height of 14 inches, the second group to an average height of 11 inches, the third to an average height of 8 inches and the last group to an average height of 4 inches.• Which group is the control group? The test groups? Control – Plants with regular water; Test – Plants with salt water Click for Answer• What is the independent variable? The dependent variable? IV – amount of salt in water; DV – height that plants grow Click for Answer• What are some constants involved in this experiment? Click for Answer Type of plant, amount of sunlight, amount of water, type of dirt, pots
Scientific Method• Important to remember: – The scientific method is a tool to help scientists solve problems. It is not set in stone and not every step is always used and its not always followed in that exact order. It is mainly a guideline. – Experimentation usually goes more like this
• What is the difference between pure and applied Science? Pure science is done for its own sake, because the scientist Click for Answer wants to know more about the world. Applied Science is done in order to improve life; to make things easier.• Which category do you think most Science done today falls into? Why?
• What are the key components of a valid experiment? – A single independent variable Click for answer – A measurable dependent variable – All other variables kept constant
• Identify the following as qualitative or quantitative observations - The car moved fast Qualitative - The car was traveling 50 mph Quantitative – The flowers were blue Qualitative – There were 5 flowers Quantitative – The ball had a mass of 10 kg QuantitativeRemember to write out 2-5 questionsabout the notes for class!!