# Practical skills Words

• Accurate When a measurement is close to the real value.
• Calibrate Check that an instrument is measuring correctly,by comparing against a standard.
• Categoric variable A variable that has a label rather than a number e.g colour.
• Continuous variable A variable that has a number rather than a label e.g 2.4W, 30cm or 4A.
• Control variable The variables that must be kept the same.
• Dependent variable The variable that you measure.
• Directly proportional As one value increases, the second value increases by the same amount.
• Discrete variable A variable that can only take specific values
• Fair test When only one variable is changed,and all others are kept the same.
• Gradient The slope of a graph
• Hypothesis A theory based on what you think.
• Independent variable The variable in an experiment that you change
• Interval The smallest division between two measurements.
• Inversely proportional If one measurement doubles, the other measurement goes down to a half.
• Peer review When a theory or set of results is reviewed and verified by other scientists.
• Precise When results are close together.
• Prediction A more detailed hypothesis where you state what you think will happen.
• Random error A random error is when an experiment produces wrong results due to a random factor.
• Range The highest and lowest results in a set of results.
• Reliable Results are reliable if they can be obtained again and again.
• Repeatable Results are repeatable if the same person repeats the same method and gets similar results.
• Reproducible Results are reproducible if two different people follow the same method and get similar results.
• Resolution A measuring device with a high level of resolution is one that is able to measure a smaller change.
• Systematic error A systematic error is when a method or piece of equipment has the same error on it and this error comes out in all of the measurements.
• Uncertainty If results could be between a number of values then we say that the result is uncertain.
• Valid Results are valid if the experiment was done as a fair test
• Variable Something that you can change in an experiment.
• Zero error When a measuring instrument gives a reading even though the true value is zero.