Basics of Educational Statistics (Graphs & its Types)
PRESENTED BY DR. HINA JALAL
Exploratory Data Analysis
A pictogram is a graphical symbol that conveys its meaning through its pictorial
resemblance to a physical object. A pictogram may include a symbol plus
graphic elements such as border, back pattern, or color that is intended to covey
specific information s. we can also say that a pictogram is a kind of graph that
uses pictures instead of bars to represent data under analysis.
A pictogram is also called “pictograph”, or simply “picto”. A pictogram or
pictograph represents the frequency of data as
Advantages and Drawbacks of Pictograms
Following are the advantages of pictograms:
• Pictograms can make warnings more eye-catching.
• They can serve as an “instant reminder” of a hazard or an established message.
• They may improve warning comprehension for those with visual or literacy
• They have the potential to be interpreted more accurately and more quickly than words.
• They can be recognized and recalled far better than words.
• They can improve the legibility of warnings.
• They may be better when undertaking familiar routine tasks.
There are a number of disadvantages of relying on pictograms.
• Very few pictograms are universally understood.
• Even well understood pictograms will not be interpreted equally by all groups of
• peoples and across all cultures, and it takes years for any pictogram to reach
• maximum effectiveness.
• They have the potential for interpreting the opposite or often undesired meaning
• which can create additional confusion.
A bar chart is a graph represented by spaced rectangular bars that describe the data points in a set of data. It is
usually used to plot discrete and categorical data.
The horizontal axis of the chart represents categorical data while the vertical axis of the chart defines discrete
data. Although the rectangular bars in a bar chart are mostly placed vertically, they can also be horizontal.
A pie chart is a circular graph used to illustrate numerical proportions in a
dataset. This graph is usually divided into various sectors, where each sector
represents the proportion of a particular numerical element in the set.
Line Graph or Chart
Line graphs are represented by a group of data points joined together by a straight
line. Each of these data points describes the relationship between the horizontal
and the vertical axis on the graph.
A histogram is a chart that groups numeric data into bins, displaying the bins as segmented
columns. They're used to depict the distribution of a dataset: how often values fall into ranges
A frequency polygon is constructed by drawing a point to represent the frequency of a particular
interval and connecting that point to the one representing the frequency
A pictogram graph uses pictures or icons to visualize a small dataset of discrete data. In a
pictogram, the icon represents a predefined unit and describes the frequency of the variables in
A radar chart is a graphical method used for displaying multivariate data in the form of a two-
dimensional chart of three or more quantitative variables represented on axes starting from the same point
A frequency polygon is a line graph of class frequency plotted against class mid-point. It can be
obtained by connecting the mid-points of the tops of the rectangles in the histogram or drawn as a line
A Frequency Curve is a smooth curve which corresponds to the limiting case of a histogram computed for
a frequency distribution of a continuous distribution as the number of data points becomes very large.
A scatter plot (aka scatter chart, scatter graph) uses dots to represent values for two different numeric variables.
The position of each dot on the horizontal and vertical axis indicates values for an individual data point. Scatter
plots are used to observe relationships between variables