Biology IA: Recording and Analyzing Data

This page gives tips on planning your project:

• Designing your lab to minimize errors
• Maximizing precision and minimizing uncertainty when collecting data
• Knowing when you've collected enough data
• Conducting the appropriate analysis of your data

Mrs. Rodenbough's Docs

• Data Collection directions
• Descriptive Data Analysis
• Inferential Data Analysis
• Data Presentation
• Conclusion & Evaluation

Discuss in your procedures the steps you are taking in your experiment to reduce errors.  Address all of the following types of error as they apply to your experiment:

In general, the precision of a tool is plus or minus half of the smallest division on the instrument.  If a thermometer reads in degrees, the precision for the thermometer is +/- 0.5 degree.  When recording a temperature, extend the significant digits to tenths of a degree to match this level of precision.   Here is an example:  14.0 ° +/- 0.5 °C

Since one must estimate the reading on a ruler at both ends of the object, the precision of a ruler is +/- the smallest increment on the ruler (2 times half the smallest increment).  Here is an example:  42 mm  +/- 1 mm.

Find the manufacturer’s estimate of precision for electronic instruments.

Be careful to be precise when measuring.  Read the bottom of a meniscus, for example.  Hold a thermometer in the substance being measured, not touching the glassware that holds the substance.  Take readings at eye level.

Estimate all sources of error in an overall estimate of uncertainty.  For example, a stop watch will have a precision based on the units given, but human reflex speed in starting and stopping the stopwatch will add additional uncertainty.