DATA PRESENTATION Flashcards
Purposes:
* primary: communicate information about the data to the user
* display data clearly and effectively
* summarize quantities of information
DATA PRESENTATION
Characteristics:
* display data
* avoid distortion of data
* allow the viewer to make comparisons
* allow the reader to think what the data convey
* allows description, exploration, tabulation or decoration
* be closely related to the statistical and verbal description of the data set
DATA PRESENTATION
- describing data by the use of statements with few numbers
- presented in paragraphs or sentences
- explain results and trends, and provide contextual information
Purpose: - to stress or emphasize significant information
Textual Presentation
Advantages:
* gives emphasis to significant data
* use for few data
Disadvantages:
* data becomes incomprehensive when large quantitative data are
included in paragraph
* paragraph involving many figures can be tiresome to most readers when
same words are repeated many times
Textual Presentation
- data are converted into words or numbers in rows and columns
- note: data should never be put in a table if it can be described in 1-2 sentences
Consideration in table construction:
* simplicity
* clarity
* directness
Tabular Presentation
Purposes:
* data checking and editing
* summarizing and presenting data
* basis, aid in graph or chart construction
Tabular Presentation
______ table
* single table which allows the distribution of observations across many
variables of interest in a given study
* each observation is cross classified across the variables which may be
quantitative or qualitative data
Purpose:
* store information with an aim of presenting detailed statistical data
* facilitate generation and tabulation of smaller table
MASTER TABLE
- self-explanatory
- all sources are specified
- headings are specific and understandable for every column & row
Tabular Presentatio
_______ table
* complete except for data
* give preview of what table outputs may be expected from the study
Purpose:
* help researcher clarify instrument
* help protocol reviewer & computer programmer
DUMMY TABLE
Tables by number of variables presented
- One-way table
- Two-way table
- Multi-way table
- pictorial representations of certain quantities plotted with reference to a
set of axes - graphs simplify complex information by using images and emphasizing
data patterns or trends - useful for summarizing, explaining, or exploring quantitative data
- present both large and small amounts of data
Graphical presentation
Advantages:
* easy to understand
* compact and concise than textual form
* presents greater detail of data than graph
* readily points out trends, comparisons and interrelations
* facilitates analysis of categories of given variable
Disadvantages:
* too many rows and columns could make it difficult for the reader to
understand the data
* requires more time to construct
Tabular Presentation
Uses:
* visually summarize the variables (data set is large)
* emphasize particular statement about data set
* enhance readability
* appeal the visual memory
Graphical presentation
- circles subdivided into a number of slices
- area of each slice represents the relative proportion data points falling
into given category - use to show how a
whole is divided
into its component
parts which could
be breakdowns of
groups or totals
Pie chart
- consists of bars of the same sizes
- horizontal or vertical with gaps between to emphasize discontinuities
- also know as one dimensional diagram
Bar graph
used for qualitative
variables
Vertical bar
graph
- used for discrete quantitative variable
Horizontal bar graph
- each bar is divided into smaller rectangles representing the parts
- area of each smaller rectangle is proportional to the relative contribution
of the component to the whole - generally used for nominal data
Component bar graph
- plot of dots joined with lines over some period of time in sequential
series - time series charts
Line graph
- bar is used to depict number or relative frequencies of data points falling
into the given class - bars are drawn over the true limits of the classes, no gaps exist in between
Histogram
similar to histogram except that:
* frequencies are plotted against the corresponding midpoints of the
classes
* adjacent points are joined with lines and the plot is tied down to the
horizontal axis resulting in multi-sided polygon
Frequency polygon
- primarily for small set of data
- provides rank-ordered lists and its easier
to restore the original value of the
observation
Stem-and-leaf plot
- shows description of a large quantitative data
- include center, spread, shape, tail length, and outlying data points
- can be presented horizontal or vertical
- height of rectangle is arbitrary and has no specific meaning
- used for comparing the distributions of several variables or the
distribution of a single variable in several groups on the same scale
Box plot
- shows the relationship between two quantitative variables
- gives rough estimate of the type and degree of correlation between the
variables
Scatter plot
