21 September 2009

Overview

Today's session will have two purposes

1. To discuss kinds of data

2. To discuss population data

I. Kinds of Data

A. Data are often classified as being qualitative or quantitative

1. Qualitative data - cannot be expressed numerically (e.g., shapes, colors, degree of health)

2. Quantitative data - can be expressed numerically

B. Quantitative data can be in the form of discrete or continuous variables

1. Discrete variables are expressed as integers (e.g., # neutrons in an atom)

2. Continuous variables are expressed as numbers and a fraction thereof (e.g., human height, percent carbon dioxide in the air)

II. Data are often used to depict information about
a population

A. Generate a histogram

B. Measures of central tendency

1. Mean

2. Mode

3. Median

C. Measures of variability

1. Range

2. Variance

3. Standard deviation

D. Histogram analysis of populations often result in a bell-shaped curve

1. Discuss population parameters in relation to curve

2. Sometimes get bimodal and trimodal distributions

3. Need to be aware of

kurtosisandskewnessin bell-shaped curve

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This page posted and maintained by Kenneth M. Klemow, Ph.D., Biology Department, Wilkes University, Wilkes-Barre, PA 18766. (570) 408-4758, kklemow@wilkes.edu.