Identifying Variable and Designing Investigations! Independent Variable: (manipulated variable) o o Also known as the INPUT variable. This is the thing that you change or manipulate, the thing that you are testing. Dependent Variable: o o o o Also known as the OUTPUT variable. This is the thing that you measure and observe. It’s the result of the experiment. You expect the dependent variable to be affected by the independent variable. Control Variable: (constant variable) o Any variable that you keep the same throughout the experiment in order to allow a “fair test” Example #1: A student thinks that year 10 students will be better at doing a quiz than a 9 or an 8 year student. Task: Dependent: Knowledge of the student. Independent: year in which the student is in Control: same test and time to complete the test. Example #2: A student has made the following prediction for an experiment, “ the more caffeine I drink the quicker my reaction time will be.” Task: Dependent: reaction time Independent: amount of caffeine Control: type of drink, method in which the reaction time is measured. Example #3: The light intensity was measured at different points moving away from a trunk of a large tree in full leaf. Task: Dependent: light intensity Independent: distance from the tree Control: same tree, measuring device, day, weather condition Example #4: Listening to music impairs your ability to study. Task: Dependent: ability to study Independent: presence or absence of music while studying Control: same topic(study material) Important information: In a graph, the vertical line is called the y axis and the horizontal axis is called the x axis. Steps in the scientific method: 1. Create a question a. aim 2. Hypothesis and research a. prediction b. reason 3. Variable a. independent b. Dependent c. control variables 4. Materials a. apparatus[capacity and type] b. chemicals[amount required]) 5. Procedure a. steps to follow in the experiment b. to be written in points and details 6. Diagram a. picture of the materials 7. Result table/ Observation table a. a table for all the observations 8. Graph 9. Graph Analysis a. What was noticed? b. Is it what you expected it to be? c. Analyze the bars or lines. d. Was your hypothesis proven correct or wrong? 10. Conclusion a. What happened? 11. Reflection a. What method did you use,? b. What did you have to figure out? c. Were you able to follow these steps? d. Were your methods reliable? e. Did you change anything in your method? f. What were the difficulties? g. What do recommend? h. If you were to spend another hour or two what other experiment would you do? 12. Precautions a. What were the safety precautions you used in your experiment? Science Materials: 1. Tripod stand a. Used to keep things above Bunsen burner 2. Multimeter 3. Beaker a. Liquid measuring container 4. Test tube a. Used as a holder of small amount of solution 5. Flat bottom flask 6. Round bottom flask 7. Glass rod 8. Stopper a. Used to prevent liquids or gas from escaping 9. Test tube rack a. Used to store test tubes 10. Droppers a. Used to transfer small amount of liquids 11. Water bathe a. Used to heat things and keep at a certain temperature 12. Mater ruler a. Measure length 13. Spring balance a. Used to measure small weighs 14. Electronic balance a. Weighing small substances 15. Triple beam balance a. Weighing substance 16. Tongs a. Used to hold small or large objects 17. Spatula 18. Crucible a. Used to heat small amount of solid substance at very high temperature 19. Wire gauze a. Used to spread heat over a burner flame. 20. Funnel a. Used to transfer liquids from one container to another without spilling 21. Centrifuge a. Used to separate liquids of different density 22. Measuring cylinder a. Measures approximate volume of liquid 23. Conical flask Question and Answer: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. A qualitative observation is a description using words only. A step by step set of instructions for completing an experiment is called method During an experiment a Bunsen burner may be used to heat substances. Another word equipment or materials is apparatus A conclusion sums up what was found out in an experiment. A logical explanation of what happened based on an observation is called an inference. Something that goes wrong but is easily avoided with care is called a mistake. A bosshead , clamp and retort stand can be used to hold equipments. Slightly inaccurate that cannot be avoided: error Safety glasses are worn to protect your eyes. A beaker would be placed above a Bunsen burner on a tripod stand. What you intend to do in an experiment is called aim. These are made using the five senses: observations A factor that can change during an experiment is called a variable Every measurement must have a unit A parallax error occurs if your eye is not level.