Unit 1 AP Biology - Experiment Design and Statistics

Line Graph

helpful for showing change of something when exposed to varying levels of the independent variable.

Pie Graph

helpful for showing the parts of a whole, with the whole being 100% of the group.

Taxis

The innate movement of an organism in response to a stimulus such as light or the presence of food.

Mode

The value that occurs most frequently in a data set.

Negative Control

a group in which no response is expected. It is the opposite of the positive control, in which a known response is expected.

Null Hypothesis

a hypothesis that says there is no statistical significance between the two variables in the hypothesis.

Standard Deviation

a measure that is used to quantify the amount of variation or dispersion of a set of data values.

Hypothesis

a proposed answer or explanation to the question that can be tested.

Mean

an average of a group of numbers or data points.

Controlled Experiment

an experiment that contains both a control group and experimental group.

Positive Control

receives a treatment with a known response, so that this positive response can be compared to the unknown response of the treatment.

Chi-Square

relating to or denoting a statistical method assessing the goodness of fit between observed values and those expected theoretically.

Dependent Variable

the condition that responds to the independent variable in an experiment.

Range

the difference between the maximum and minimum observations.

Constants

the factors that do not change in an experiment.

Median

the middle number in a given sequence of numbers, taken as the average of the two middle numbers when the sequence has an even number of numbers:

Degrees of Freedom

the number of "observations" (pieces of information) in the data that are free to vary when estimating statistical parameters.

Control Group

the part of an experiment which is not exposed to the independent variable.

Experimental Group

the part of the experiment that is exposed to the independent variable.

Standard Error

the standard deviation of the sample-mean's estimate of a population mean.

Independent Variable

the variable that is manipulated / changed in an experiment.

Bar Graph

used to compare groups or variables of an experiment.