P2.1. Data Presentation Flashcards
Types of Data Presentation:
- Textual presentation
- Tabular presentation
- Graphical presentation
display clearly, effectively, and summarizes quantities of information.
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
stress or emphasize significant information
Textual Presentation
- gives emphasis to significant data
- use for few data
Textual Presentation
- 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
- data should never be put in a table if it can be described in 1-2 sentences
Tabular Presentation
Consideration in table construction:
- simplicity
- clarity
- directness
- data checking and editing
- summarizing and presenting data
- basis, aid in graph or chart construction
Tabular Presentation
7 Components of Tabular Presentation:
Table number
Title
Row Headings/Stubs
Column Headings/Captions
Body of the Table
Source Note
Footnote
- self-explanatory
- all sources are specified
- headings are specific and understandable
- row & columns are checked for accuracy
- cells are not left blank; enter “0” or “-“
- exclusive & exhaustive categories
Tabular Presentation
2 types of tabular presentation:
- Master Table
- Dummy 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
- allow the smaller generation of smaller tables
- store information with an aim of presenting detailed statistical data
- facilitate generation and tabulation of smaller table
Master Table
- complete except for body
- give preview of what table outputs may be expected from the study
- help researcher clarify instrument
- help protocol reviewer & computer programmer
Dummy Table
3 types of tables by number of variables presented:
- tables with only one variable
- tables with two variables
- tables with three or more variables
- One-way table
- Two-way table
- Multi-way table
-
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
Tabular Presentation
- too many rows and columns could make it difficult for the reader to understand the data
- requires more time to construct
Tabular Presentation
- Pictorial representations of certain quantities(frequency) plotted with reference to a set of axes(x – horizontal; y – vertical)
- 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
- few data (< 3)
- small amount of data (= or > 3)
- small and large data (< or = or > 3)
- textual
- table
- graphical
- visually summarize the variables (data set is large)
- emphasize particular statement about data set
- enhance readability
- appeal the visual memory
Graphical presentation
- include, below the figure, a title providing all relevant information
- be referred to as figures in the text
- identify figure axes by the variables under analysis
- quote the source which provided the data, if required
- demonstrate the scale being used
- be self-explanatory
Graphical presentation
Types of Graphical presentation:
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- pie chart
- bar graph
- component bar graph
- line graph
- histogram
- frequency polygon
- stem-and-leaf plot
- box plot
- scatter plot
- 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
- bars of the same sizes
- height & length = quantities of variables
- Horizontal or vertical with gaps between to emphasize discontinuities
- Also known as ONE DIMENSIONAL DIAGRAM
- height of bars/rectangles: quantity of variables
BAR GRAPH
2 types of Bar Graph:
1. w/ only one variable
2. w/ two or more variable
- simple bar graph
- multiple bar graph
- Height of bars should be proportional to the frequencies or rates of categories
- Width of bars should be equal
- Percentages & rates must be used when total number of observations for the groups are not uniform
- When percentages are used, the sum of the heights of all the bars must be equal to 100%
- To make them more appealing, bars are either colored or shaded in different ways
BAR GRAPH
- used for qualitative variables
- used for discrete quantitative variables
- horizontal bar graph
- vertical bar graph
- bar is divided into smaller rectangles
- smaller rectangle is proportional to the relative contribution of the component of the whole
- used for NOMINAL DATA
- different shades or colors emphasize differences between parts of the whole
- Preferable over the pie in situations where the compositions of two or more groups are to be compared
Component bar graph
- Plot of dots joined with lines over some period of time in sequential series
- TIME SERIES CHARTS
- Horizontal axis: ?
- Vertical axis: ?
Line Graph
- hori = time series
- verti = variable values
Scale:
frequency and percentage are used if the measure is distribution.
rate is also a measure, you can also use other like proportion, mean, median, etc. but frequency and distribution are mostly used.
- 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
- preferred for grouped interval data
- horizontal axis: ?
- vertical axis: ?
HISTOGRAM
- continuous quantitative
- number of relative frequencies
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
- for small set of data
- rank ordered lists
- easier to restore the original value of the observation
- lines gives more information than bars in histogram
- show the actual data value instead of using bars to represent the height of an interval
Stem-and-leaf plot
- shows description of a large quantitative data
- can be presented horizontal or vertical
- height of rectangle is arbitrary and has no specific meaning
- 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
- main feature & implications of the body of data can be grasped at a glance
- more attractive & appealing to a wider range of readers
- simplifies concepts that would otherwise have been expressed in so many words
-
shows trends & patterns of a large set of data
* comparisons could be made more striking - can be readily clarify data
Graphical presentation
- cannot show as many sets of facts
- can only show approximate values
- require more time to construct
- may be used to misinterpret results
Graphical presentation
