LECTURE 8

INTRODUCTION TO INFORMATION TRANSFER

OBJECTIVESBy the end of the lecture, students should be able to:Differentiate the different kinds of graphs and charts.Read and interpret information from tables, graphs, charts & pictures.

TypesTables used to organize exact amounts of data & display information. show numerical specifics rather than visual comparisons, & therefore take longer to read and understand. difficult to examine overall trends or comparisons than using bar and circle graphs. Line & Bar Graphs used to compare data and show trends. provide a display that enables the reader to quickly examine these trends visually. can be difficult to read accurately.A change in the interval and/or scale may alter the visual perception of data, which may persuade or trick the readerPie Charts used to compare parts to a whole.They visually represent data in the same proportion as the numerical data in a table.

TABLES

Purpose of tablesprovide informationFrequently one quantity in a table depends upon or is related to another.Data from tables can be graphed to aid interpretation.Graphs give a visual representation of the data that helps to reveal regularities and patterns

Example Table showing the major trade partners of Singapore and their share in its total trade.( CIA reports for 2009)

Exports Imports Hong Kong11.6%US14.7%Malaysia11.5%Malaysia11.6%US11.2%China10.5%Indonesia9.7%Japan7.6%

Table showing worlds biggest cities and population in million

CityCountryPopulationMumbai (Bombay)India12 millionSao PauloBrazil10.5 millionSeoulSouth Korea10 millionKarachiPakistan9.8 millionDelhiIndia9.8 millionShanghaiChina9.2 millionJakartaIndonesia9.1 millionMexico CityMexico8.5 millionIstanbulTurkey8.1 million

Data from a table can be visually represented in a graph

A SURVEY INTO BOYS AND GIRLS LEISURE TIME ACIVITIES(Average hours spent per week)ActivitiesBoyshours GirlshoursWatching cartoons2314.32364.4Playing with friends2354.22444.4Playing computer games2093.11771.7Playing alone with toys1953.12012.8Reading1872.72003.3Playing with parents1772.31782.6Watching TV films2012.22042.6Watching sport on TV1201.1551.725017.925017.6

A(1) ___ was undertaken among a group of (2) __ hundred primary schoolchildren in order to(3) ___ the most popular leisure time activities of boys and girls. For the most part(4)___ patterns were found, with boys and girls enjoying the same things and spending roughly the (5) ___ amounts of time on each. However, only a small(6)____ of the girls said that they regularly watched (7)___on t.v. whereas most boys said that they did. Boys spent (8)___time than girls playing computer (9)____and girls read more(10)___ boys in their free time.

Five sportssurveycomparemoreproportionthansamesimilargames

Graphs and Charts

Main PurposesTo emphasize the main numerical factsTo reveal important facts, comparisons, & relationships which might be overlooked or not quickly ascertained in text and tables.

Graphs have many features in common

Title that describes what the graph shows.Grid that is used to plot points or other data.Horizontal or X axis that is labeled with the name of a variable & the units represented.Vertical or Y-axis that is labeled with the name of a variable & the units represented.

Types of Graphs and Charts

Line graphBar graphGrouped Bar graphsPaired Bar graphsPie-chart Flow-chart Pictographs

LINE GRAPH Compares 2 variables. Each variable is plotted along an axis . A line graph has a vertical axis and a horizontal axis. Widely used.

The Bar Graph

is a visual display used to compare the amounts or frequency of occurrenceof different characteristics of data.

BAR GRAPH Bar graphs are an excellent way to show results that are one time, that are not continuous - especially samplings such as surveys, inventories, Price of Corn versus Quantity Demanded

C0LUMN GRAPHSSimilar to bar graphs and line graphs. They have grid lines going horizontally & vertically.

C0LUMN GRAPHSThe column graph is used more for one time or single events rather than continuous events.

The data is presented in columns. The category names can be on the graph or underneath the column.

Not necessary to assign different colours to the columns. If you do so attach a legend that explains the different colours & which category they stood for.

Double ( grouped )Bar Graphs

Each data group is represented by two bars. are used for when each data group contains two different sets of frequency data. allows the comparison of a number of items in two (sometimes three) aspects at the same time by means of connected adjacent horizontal bars opposite each sub item

Below is an example of a table that has two frequency data values per data group.

Quarterly Reports of Income and Expenses for Dry Cleaning Associates and Co.QuarterIncome (thousands of dollars)Expenses (thousands of dollars)First Quarter5739Second Quarter10780Third Quarter7378Fourth Quarter11882

Look at the bar graph that illustrates the data presented in the table above

Quarterly Reports of Income and Expenses for Dry Cleaning Associates and Co.

When reading double bar graphs, we often want to look at the difference in heights between the two data bars within one group. For example, the difference between the income and expenses bars for each individual quarter tells you the profit for that quarter (profit = income expenses).

By paying attention, not only to individual bar heights, but differences between bar heights, you can make more generalizations from double bar graphs.

Task : Use the double bar graph shown above to complete the following questions

Is it true that if the Dry Cleaning Associates' income is over $60,000, then their expenses are also over $60,000? Explain your answer. In what quarters did the company experience its biggest profit and the biggest loss? Approximate both values. Overall, did the Dry Cleaning Associates experience a profit or a loss for the year?

Task: Given the double bar graph, answer the questions below.

Imports and Exports of Selected Countries as percentages of GDP, 1992-1993

QuestionsWhich nation has the greatest difference between the level of imports and exports? Approximate that difference in billions of dollars. Which countries shown on the graph import more than they export? Is it true that the higher the amount of imports and exports a nation has, the more likely it is that there is a balance between imports and exports? Explain your answer.

The Paired Bar Chart also compares a number of items in two aspects at the same time. Instead of being grouped, the bars are placed opposite to each other, one set for one of the comparisons on the right of the items caption and the second set for the other comparison on the left.

Net Exports of Selected Nations Example

Task: Using the bar graph which is shown below, answer the following questions.

QuestionsWhich nation has the highest level of net exports? Approximate this level, in billions of dollars. What is the largest difference in net exports between two nations shown on the graph? Britain's net export level is closest to which other county's level of net exports?

The Subdivided Bar Chart shows each bar divided into its component parts. Most often the largest or the most important component is put next to the zero line because only the component that starts from zero can be measured directly on the amount scale.

Pictographs

Uses cartoons or simple drawings to depict quantities. Makes abstract comparisons more concrete. Use silhouette (pictures), leaving out detail. Best for data with a large difference . Good for young audiences.

This pictograph shows quantities: how many legs (but not their relative sizes), how many wings (but not where they are located, or how they are grouped in pairs).

A pictograph is any graph in which small pictures/symbols are used, like the wings and legs in this graph.

Pie Chart (Circle graphs )A pie chart is a way of illustrating information by using sectors of a circle to represent parts of the whole. Each sector is proportional in size to the amount each sector represents, therefore it is easy to make generalizations and comparisons. Pie charts are display percentages. Therefore, they are used to compare different parts of the same whole.

Reading a pie chartExample

Important to make statements about sectors of the graph, relative to one another, and relative to the entire circle.

From this one example, we can see the amount of information we can get, and all from looking at one circle graph! Now, let's try an example of reading a circle graph and answering specific questions about the data presented.

Using Pie chart to compare

The following pie charts show an analysis of the destinations of pupils leaving a sixth form college.

Task: Which of the following statements are true?

1)More pupils went into higher education in 1994 than in 2003 2)136 pupils went into employment in 2003 3)More pupils decided on a gap year in 2003 than in 1994.

FLOW CHART Graphically show the sequence of events or the process. Shows the relationship of steps in the process but not of different things.

ORGANIZATIONAL CHART

Showing organizational relationships. Chain of commands. How one department relates to another. Direct and indirect relationships.

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