Statistics & Controlled Experiments Study Guide

null hypothesis

• The null hypothesis states that there will be no significant difference in the experimental outcome.  

alternative hypothesis

The alternative hypothesis states that a particular outcome will be observed.

independent variable

the variable that is manipulated during an experiment,

dependent variable

what you measure in the experiment and what is affected during the experiment

experimental group

the group in an experiment that receives the variable being tested

constants

The factors that do not change during the experiment.

positive control group

exposed to a treatment known to produce results.

negative control group

exposed to a treatment that produce normal or no results.

variance

in a data set measures the how much data differ from their mean (average)

standard deviation

1. Represents variance in data.

• Not significance

standard error of mean

Represents probability of data being statistically significant (must be +/- 2*SE).

statistical significance

is the error bars over lap there is no significance if they dont then there is significance

correlation

the statistical relationship between two variables, indicating how closely they move together

legend

a visual reference that explains the meanings of different colors, shapes, or patterns used to represent data.

mean

mean, which is calculated by dividing the sum of the values in the set by their number.

axis break

a visual representation that indicates a discontinuity or break in the scale of either the x or y axis

equidistant

at equal distances.

line of best fit

a straight line that minimizes the distance between it and some data