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# Experiment Variables and Data Analysis ## Variables * **What is a variable?** Something that can change in an experiment. * **What are the three types of variables?** Dependent, independent, and control. * **Which variable is the one that scientists change during an experiment?** Independent var...

# Experiment Variables and Data Analysis ## Variables * **What is a variable?** Something that can change in an experiment. * **What are the three types of variables?** Dependent, independent, and control. * **Which variable is the one that scientists change during an experiment?** Independent variable. * **Which variable is the one that scientists measure as a result of an experiment?** Dependent variable. * **Which variables are kept the same during an experiment?** Control variables. * **Why do we need to keep control variables the same in an experiment?** So only one thing is changing the dependent variable. ## Experiment Design * **IV: Temperature of water** * **DV: Mass of salt dissolved** * **CV: Volume of Water** ## Scientific Concepts * **What is a hypothesis?** A prediction about what will happen in an experiment, supported by an explanation. * **What three parts must a risk assessment include?** Hazard, risk, safety precaution. * **What is a hazard in an experiment?** Something that has the potential to cause harm or damage. * **What is a risk in an experiment?** How the hazard could cause harm or damage. * **What is a safety precaution in an experiment?** What you will do to stay safe during the experiment. * **What is a measurement?** The result of an experiment that can be measured with scientific equipment. *Examples:* Mass, distance, time, force, wavelength, temperature. * **What is an observation?** Something that can be seen in an experiment; *Examples:* Colour, giving off light, giving off gas, movement, change in state. * **What is continuous data?** Numerical data where the number can be any size. *Examples:* Mass of a substance * **Why is the mass of a substance continuous data?** Because the mass can be any number. * **What is discrete data?** Data which can be put into categories (groups). *Examples*: Eye colour (e.g., blue, brown) * **Why is eye colour discrete data?** Because the different colours can be categorized. * **What is a table of results?** A table showing experimental data where the independent variable is on the left, the dependent variable on the right, and each column has a header with units. * **What are the key features of a table of results?** Independent variable on the left, dependent variable on the right; each column has a heading with units. * **Why do scientists draw graphs?** To more easily see patterns in data, to make predictions for values that weren't measured. * **When are bar charts used?** If independent variable is discrete. * **When are line graphs used?** If independent variable is continuous. * **What are the key features of a good graph?** Appropriate scales, axes drawn, line of best fit (straight line or curved), labels on axes (including units), title. * **Which axis does each variable go on when drawing a graph?** Independent on the x-axis, dependent on the y-axis. * **What is a scale on a graph?** The numbers along the axes. * **How should scales be drawn?** Goes up in a sensible number (1, 2, 5, 10) and is evenly spaced.