Lab Safety & Experimental Design Review Notes review

Science Science is the use of evidence to construct testable explanations and predictions of the physical and natural world, as well as the knowledge generated through this process. Science only answers questions that are testable by a process called scientific inquiry- the planned and deliberate investigation of the natural world

Science Divided into three major branches: Natural: The study of natural phenomena Formal: The study of mathematics and logic Social: The study of human behavior and societies Aquatic science falls under Natural Science Natural science has many branches including Biology Aquatics is a subdivision of Biology

Scientific Inquiry When answering scientific questions there are a variety of ways to conduct your investigation. Comparative: A comparison of 2 or more things Descriptive: Observable lab investigations; including two types of data Qualitative: involves Qualities Collected by observing, looking & listening Examples: Colors, smells, things you can see or taste, etc. Quantitative: involves Quantities Collected by measurements Examples: length, height, temperature, weight, cost, ages, etc. Experimental: Designed experiment that follows the scientific method Has a clearly defined control and test group

Scientific Method Misleading because it is process not reserved for biologist and other scientists Also it is not a methodical set of steps to be followed in a specific order It is an organized pattern of thinking to solve everyday problems It is problem-solving technique that involves a series of steps that can be used to think through most problems

Setting Up the Experiment Control Group: is a setup used for comparison Experimental Group: the group exposed to the factor being tested Variable- factor changed by the experimenter. Only one factor should be changed at a time. Independent (Manipulated) Variable-The factor used to test the hypothesis; it might affect the outcome of the experiment. Dependent (Responding )Variable: it results from or depends on changes to the independent variable. Constant: Factors that remains fixed during an experiment while the independent and dependent variables changes.

Define the Parts of this Experiment Michael put 100 red seeds, 100 brown seeds, and 100 yellow seeds in his bird feeder. He also put in his bird feeder 100 sunflower seeds that the birds normally eat in their diet. He counted the number seeds of each color that remained after 2 days. He repeated this experiment 10 times over a 20 day period. He kept the bird feeder in the same place and thoroughly mixed the seeds together. Independent, dependent, constants, control, hypothesis (make one you could test from the scenario).

Reviewing Results Circle Graph- used to show relationship of a part to a whole to show relative sizes of data Bar graph- Used when independent variable isn’t continuous are good when your data is in categories Line graph- Used when independent variable is continuous shows information that is connected in some way (such as change over time) Manipulated variable is plotted on the X axis Responding variable is plotted on the Y axis

Data Analysis & Conclusion After collecting data, analyze the data and form conclusions based on the following questions Do the results support or refute the hypothesis? Is more data needed? Are different procedures needed? Is the experimental set-up valid? Was there a large enough sample size? Were the sources of errors minimized? Was there only one variable tested? Is the experiment repeatable? Conclusion Scientists report their findings and conclusions in scientific journals.

Reviewing Data & Making Conclusions Proof: using supportive information to establish something as true or fact Evidence: the available body of facts or information indicating whether a belief or hypothesis is valid or true Circumstantial: cannot directly point to a fact but instead must be inferred Direct: Evidence that proves or disproves something believed to be fact due to being experienced, seen, heard etc. Which is more reliable? Does proof exist in science?

Scientific Theory An explanation of natural or physical phenomenon supported by many observations and experiments over time. Tested by multiple independent researchers Complex explanations and have been supported by years of scientific research They are considered valid until new areas of study are developed or until new technologies are developed and new evidence is found.

Scientific Hypothesis A educated guess that has clearly defined parameters and is stated as an “If, Then” statement It must be a testable idea that can be researched If you study 30 minutes everyday while listening to music at 7 pm at the kitchen table, then you will increase your test grades by one letter grade. Spending time with puppies everyday will make you a happier person.

Scientific Law An explanation of natural or physical phenomenon supported by many observations and experiments over time. Tested by multiple independent researchers. Complex explanations and have been supported by years of scientific research They are considered valid until new areas of study are developed or until new technologies are developed and new evidence is found.

Theory vs Law vs Hypothesis When a hypothesis is tested many times and the explanation is durable, the hypothesis can be incorporated into a theory. A Scientific Theory is a well-established and highly reliable explanation Theories will never be laws Laws will never be reduced to theories Theories explain why something occurs Laws define something that occurs in nature but doesn’t explain why Laws are most reliable, then theories, and then a hypothesis

Lab Safety When conducting experiments one of the most important things to follow is lab safety Basic lab safety includes several categories: Clothing Safety Disposal Safety General Safety Accident & Injury safety Chemical Safety Glassware Safety Heating Safety With a partner review as many rules in each category as you can. On a sheet of paper list as many as you can in the next 30 seconds.

Lab Safety Symbols to recognize when beginning a lab to ensure we use proper lab safety

Lab Safety