Biostat Mod 3: Data Presentation in Biostatistics and Epidemiology

Textual Presentation

Data presented in raw and vague form, generally as a paragraph, useful for supplementing qualitative statements with data; emphasizes significant figures and comparisons ; data is not very large

Tabular Presentation

Data organized in rows and columns for easy reading and comparison;

components of data tables

heading, box head, stub, field, source note, and foot note.

heading

consists of table number, title, and headnote

table number

for ease of access and locating ; can be sued anywhere in the book/paper which leads us directly to the data mentioned

title

brief statement of nature, classification, time reference, and area/location

head note

statement that provides additional information

box head

contains column heads together with classifying and qualifying spanner heads ; column labels should be precise ; spanner heads are added if two or more adjacent columns begins and ends with the same phrase

stub

comprises the first column on the left ; also known as stub column ; usually lists the major independent or predictor variables

field

main part of the table ; contains the substance or figures of the data

source note

exact citation of the source of data presented in the table

foot note

any statement or note inserted at the bottom of the table

Graphical Presentation

includes geometrical figures like lines, bars, circles, squares, etc ; allows us to understand the data in an easier manner

qualities of a good graph

accuracy, clarity, simplicity, appearance

accuracy

should not be deceptive, distorted, misleading, or in any way susceptible to wrong interpretations

clarity

can be clearly read and understood

simplicity

the basic design should be simple and straightforward

appearance

designed and constructed to attract and hold attention by having a neat, dignified, and professional appearance

Line Diagram

Graphical representation where independent data are on the horizontal axis and dependent data on the vertical axis; used to display change over time with connected data points.

Bar Graph

Graphical representation of categorical data with horizontal or vertical lines proportional to the value of the item; you can choose an arbitrary width of bar but keep it constant ; gaps between bars should be constant.

Pie Chart

Circular chart with the radii dividing areas into sectors proportional to component values; useful for displaying data when components are not more than 6 and values are dissimilar ; the whole circle represents the entire data under investigation

Pictorial Unit Chart

Chart where each symbol represents a specific and uniform value.

histogram

graphical representation of quantitative data