Physics: Working Scientifically

Control

The sample in an experiment o which all the other samples are compared to.

Dependent Variable

The factor in the experiment that is measured and usually plotted on the y-axis.

Hypothesis

A prediction of an experimental outcome.

Independent Variable

The variable that is deliberately changed within an experiment and usually plotted on the x-axis.

Plausible Accuracy

The accuracy estimated taking into considerations sources of errors and limitations of instruments.

Quantitative

Measured Components

Reliability

The degree in which repeated observations or measurements taken under identical circumstances yield the same result.

Validity

The extent to which the processes and resultant data measure the intended purpose of the experiment.

Variables Held Constant

Factors that may vary, but are deliberately held constant for the purpose of maintaining the validity of an experiment.

Absolute Error Formula

(True Value-Observed Value)

Relative Error (%) Formula

(True Value-Observed Value)/True Value

Systematic Errors

Errors that cause a constant displacement of value.

Random Errors

Errors that cause scattered values of no inherent pattern.

Uncertainty Formula

±(highest trial=lowest trial)/2

Internal Reliability/Precision

When repeated trials within an experiment are consistent.

External Reliability

When the results from one experiment are consistent with those from other experiments that are conducted the same way.

Accuracy

Closeness of an observed value to its “true” value.