A
chart is a graphical representation of data, in which "the data is
represented by symbols, such as bars in a bar chart, lines in a line
chart, or slices in a pie chart". A chart can represent tabular numeric
data, functions or some kinds of qualitative structures.
Charts are
often used to ease understanding of large quantities of data and the
relationships between parts of the data. Charts can usually be read more
quickly than the raw data that they are produced from.Certain types of
charts are more useful for presenting a given data set than others. For
example, data that presents percentages in different groups (such as
"satisfied, not satisfied, unsure") are often displayed in a pie chart,
but may be more easily understood when presented in a horizontal bar
chart. On the other hand, data that represents numbers that change over a
period of time (such as "annual revenue from 1990 to 2000") might be
best shown as a line chart.
Bar Chart
A bar chart or bar graph is a chart with rectangular bars with lengths proportional to the values that they represent. The bars can be plotted vertically or horizontally. A vertical bar chart is sometimes called a column bar chart.Bar charts provide a visual presentation of categorical data. Categorical data is a grouping of data into discrete groups, such as months of the year, age group, shoe sizes, and animals.
A bar chart or bar graph is a chart with rectangular bars with lengths proportional to the values that they represent. The bars can be plotted vertically or horizontally. A vertical bar chart is sometimes called a column bar chart.Bar charts provide a visual presentation of categorical data. Categorical data is a grouping of data into discrete groups, such as months of the year, age group, shoe sizes, and animals.
A pie chart (or a circle graph) is a circular chart divided into sectors, illustrating proportion. In a pie chart, the arc length of each sector (and consequently its central angle and area), is proportional to the quantity it represents.
A line chart or line graph is a type of chart which displays information as a series of data points connected by straight line segments.
In statistics, a histogram is a graphical representation showing a visual impression of the distribution of data. Histograms are used to plot density of data, and often for density estimation: estimating the probability density function of the underlying variable.
Example of chart analysis :
Bar Chart
The White Non-Hispanic racial group is the largest racial category. The proportion of enrollees who were classified as White Non-Hispanic or Black has decreased since 1999 (43.35% white in 1999 and 40.73% in 2007; 25.24% black in 1999 and 22.13% in 2007), whereas the proportion who were Asian or Pacific Islander increased from 2.71% in 1999 to 3.79% of enrollees in 2007, and the proportion who were classified as Hispanic or Hispanic and another race increased from 18.63% in 1999 to 23.9% in 2007.
Pie Chart
The age distribution of the Medicaid population is heavily skewed toward the younger population. Twenty percent of the Medicaid population is 5 years of age or younger; and 54% are 20 years or younger. Slightly fewer than 10% are 65 years of age or older.
This
is only the simple analysis of chart. You can develop the statement to
expand your analysis, but dont forget not to out of topic or giving
false statement or add things that couldn't seen on the chart. For tips,
take a note of some important words or phrases that help you to develop
your description, such as: increased, decreased, slightly fewer than,
fell down at, etc.
source: wikipedia.com (chart description), ccwdata.org (example)
