Evidence
Repeatable
Same person does an experiment again using same methods/ equipment and get similar results
Reproducible
Someone else does the experiment/ uses different method or piece of equipment is used to get
similar results
Variables
Dependent - measure
Control - keep same
Independent - change
Sample sizes
A sample should represent the whole population
Small samples = harder to spot anomalies
Accuracy Vs precision
Accuracy
Results close to the true answer
Precision
All the data is really close to the mean of repeated results (spread of values in small)
Resolution
Smallest change a measuring instrument can detect
Errors
What is an error?
Distance between the measured value and the true value
Random error
Error caused by factors that vary between readings e.g. reaction time
Parallax error
Error caused by observing apparatus at an angle
Systematic error
Error that causes every reading to be different from their true values by the same amount
Zero error
Systematic error caused by equipment not be calibrated or zeroed before measuring
Categories of data
Discrete
Numerical data that can only take certain values
Use a bar chart (also bar charts are used when independent variable is categoric)
Continuous
Numerical data that can have any value within a range
Use a graph
Repeatable
Same person does an experiment again using same methods/ equipment and get similar results
Reproducible
Someone else does the experiment/ uses different method or piece of equipment is used to get
similar results
Variables
Dependent - measure
Control - keep same
Independent - change
Sample sizes
A sample should represent the whole population
Small samples = harder to spot anomalies
Accuracy Vs precision
Accuracy
Results close to the true answer
Precision
All the data is really close to the mean of repeated results (spread of values in small)
Resolution
Smallest change a measuring instrument can detect
Errors
What is an error?
Distance between the measured value and the true value
Random error
Error caused by factors that vary between readings e.g. reaction time
Parallax error
Error caused by observing apparatus at an angle
Systematic error
Error that causes every reading to be different from their true values by the same amount
Zero error
Systematic error caused by equipment not be calibrated or zeroed before measuring
Categories of data
Discrete
Numerical data that can only take certain values
Use a bar chart (also bar charts are used when independent variable is categoric)
Continuous
Numerical data that can have any value within a range
Use a graph
