### measurement

is a comparison of a dimension of an object or substance to an appropriate standard, usually an instrument with a calibrated scale.

### instrument

any artificial device made for the purpose of refining, extending or substituting for the humans senses when measuring

### measured data

has two parts:

1) a number that gives the size of the measurement

2) dimensional unit

### observational bias

is a flawed perspective on data that results from a person's desire to see a certain outcome

### objective observation

a more precised(exact) observation, more accurate-(it is not possible to be exact, but close)

### SI

Le Système International d'Unités, or the International System of Units, which is the measurement system that is accepted worldwide...METRIC SYSTEM

### significant digit (SD)

a digit in the measurement used to communicate the precision of the measurement.

### scientific notation

a convenient way to express very large or small numbers in the form of M x 10, an expression of numbers in the form m × 10n where m is equal to or greater than 1 and less than 10, and n is an integer, a way of writing very large or very small numbers using a number between 1 and 10 multiplied by a power of ten

### spring scale

an instrument that measures weight by balancing the pull of the earth's gravity on the object being weighed

### electronic balance

an electronic instrument that measures the weight of an object and then displays is equivalent mass

### balance

an instrument that compares a known mass to an unknown mass. when balanced the weight of the object with unknown mass equals the weight of the known mass.

### electronic scale

object to be weighed is placed on a metal plate on top of the instrument. the scale converts the pull of gravity on the object into an electronic signal - weight is displayed on a digital screen.

### Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through Flickr.com. Click to see the original works with their full license.