DATA
PRESENTATION
Tabular and Graphical Presentation of Data
JILLIAN MARIE M. CUEVAS, RMT, MSMT
Course Facilitator
LEARNING EXPECTED OUTCOMES
▪ Explain the purpose and importance of data
▪
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▪
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presentation
Enumerate the essential components of a table
Discuss the meaning of graphs
Enumerate the advantages and disadvantages of
graphical presentation of data
Identify appreciate graphs to use for a given data
Discuss the description and function of the different
graphs
Review
Basic concepts
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Pictures of Data
▪ Depict the nature or shape of the data
distribution
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METHODS OF PRESENTING DATA
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▪
Textual
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Tabular
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Graphical
DESCRIPTIVE STATISTICS
2. Summarize data
1. Organize data
▪ Central Tendency (or Groups’ “Middle
▪ Tables
Values”)
• Frequency Distributions
• Mean
• Relative Frequency Distributions
▪ Graphs
▪• Bar Chart or Histogram
▪• Stem and Leaf Plot
▪• Frequency Polygon
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▪
• Median
• Mode
Variation (or Summary of Differences
Within Groups)
• Range
• Interquartile Range
• Variance
• Standard Deviation
WHAT IS A FREQUENCY
DISTRIBUTION
Suppose we ask a sample of 30 teenagers each to tell us how old they are. The list of their
ages is shown in Table 5.1
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FREQUENCY DISTRIBUTION
It is now easy to see how often each age occurs
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FREQUENCY DISTRIBUTION
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▪
A table listing all classes and
their frequencies
▪
For nominal and ordinal data, a
frequency distribution consists
of a set of classes or categories
along with the numerical counts
that correspond to each one.
FREQUENCY DISTRIBUTION
▪ To
display discrete or
continuous data in the form
of a frequency distribution,
break down the range of
values of the observations
into a series of distinct, nonoverlapping intervals.
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RELATIVE FREQUENCY
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▪
The proportion of the total number of
observations that appears in that interval.
▪
It is computed by dividing the number of
values within an interval by the total number
of values in the table, multiplied by 100% to
obtain the percentage of values in the interval.
▪
Relative frequencies are useful for comparing
sets of data that contain unequal numbers of
observations
RELATIVE FREQUENCY
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CUMULATIVE RELATIVE FREQUENCY
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▪
Is the percentage of the total
number of observations that have a
value less than or equal to the
upper limit of the interval
▪
It is calculated by summing the
relative
frequencies
for
the
specified interval and all previous
ones.
CUMULATIVE RELATIVE
FREQUENCY
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Text Presentation
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Main method of conveying information as it is used to explain results
and trends, and provide contextual information.
Data are fundamentally presented in paragraphs or sentences.
For instance, information about the incidence rates of delirium
following anesthesia in 2016–2017 can be presented with the use of
a few numbers:
▫
“The incidence rate of delirium following anesthesia was 11% in
2016 and 15% in 2017; no significant difference of incidence
rates was found between the two years.”
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If this information were to be presented in a graph or a table,
it would occupy an unnecessarily large space on the page,
without enhancing the readers' understanding of the data
Table Presentation
▪ Convey information that has been converted into
words or numbers in rows and columns.
▪ Tables are the most appropriate for presenting
individual information, and can present both
quantitative and qualitative information.
▪ Useful for summarizing and comparing quantitative
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information of different variables and information
with different units can be presented together
Graph Presentation
▪ Graphs simplify complex information
by using images and emphasizing
data patterns or trends, and are
useful for summarizing, explaining,
or exploring quantitative data.
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GRAPHICAL PRESENTATION OF DATA
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A. BAR CHARTS
▪ Popular type of graph used to display a frequency
distribution for nominal or ordinal data.
▪ In a bar chart, the various categories into which the
observations fall are presented along a horizontal axis.
▪ A vertical bar is drawn above each category such that the
height of the bar represents either the frequency or the
relative frequency of observations within that class.
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B. HISTOGRAMS
▪ A histogram depicts a frequency
▪
distribution for discrete or continuous
data.
It is a bar graph in which the horizontal
scale represents classes and the
vertical scale represents frequencies.
▪ The horizontal axis displays the true
▪
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limits of the various intervals.
The true limits of an interval are the
points that separate it from the
intervals on either side.
HISTOGRAM
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C. PARETO CHART
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D. PIE CHART
▪ Useful
for
comparing
individual categories with
the total.
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E. FREQUENCY POLYGONS
▪ It is constructed by placing a point at the center of each
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▪
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interval such that the height of the point is equal to the
frequency or relative frequency associated with that
interval.
Points are also placed on the horizontal axis at the
midpoints of the intervals immediately preceding and
immediately following the intervals that contain
observations.
The points are then connected by straight lines.
FREQUENCY POLYGONS
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FREQUENCY POLYGONS
Rating
(Midpoint) Frequency
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0 - 2 (1)
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3 – 5 (4)
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6 – 8 (7)
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9 – 11 (10)
2
12 - 14 (13)
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F. SCATTER PLOTS
One-Way Scatter Plots
▪ Another type of graph that can be used to summarize a
set of discrete or continuous observations.
▪ Uses a single horizontal axis to display the relative
position of each data point in the group.
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F. SCATTER PLOTS
Box Plots
▪ Box plots are similar to one-way
scatter plots in that they require
a single axis; instead of plotting
every observation, however,
they display only a summary of
the data
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F. SCATTER PLOTS
Two-Way Scatter Plots
▪ Used
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to
depict
the
relationship between two
different
continuous
measurements.
▪ Each point on the graph
represents a pair of values;
▪ The scale for one quantity is
marked on the horizontal axis,
or x-axis, and the scale for
the other on the vertical axis,
or y-axis.
G. Line Graphs
▪ Similar to a two-way scatter plot in that it can be used
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to illustrate the relationship between continuous
quantities.
Each point on the graph represents a pair of values.
Adjacent points are connected by straight lines
Useful for representing time-series data
Useful for studying patterns and trends across data
Also appropriate for representing not only time-series
data, but also data measured over the progression of a
continuous variable such as distance.
LINE GRAPHS
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LINE GRAPHS
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OTHER PICTURES OF DATA
Dot Plot
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OTHER PICTURES OF DATA
Stem-and Leaf Plot
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THANKS!
Any questions?
You can find me at:
jmcuevas@fatima.edu.ph
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