Commenting a graph or chart could be a great exercise to develop our English skills and, at the same time show and put into practice our knowledge in a certain field.
Charts or graphs help us to display a great amount of information in a visual and graphical way, so we can get an idea of a complex process and visualize and compare trends easily.
As, you might have seen in class, we have to distinguish into four different parts or phases of a graph’s commentary:
- Introduction.
- Description.
- Analysis.
- Conclusion.
- Introduction:
In this part, we have to classify the type of graph or chart we are going to analyse and comment, and we should also mention the main process or event that is displayed in the graph.
When we describe the kind of the chart, we could distinguish into: line graphs (simple if there is only one line, or multiple if there are more than one line), pie charts, flow charts, bar graphs or bar charts or histograms, tables or diagrams.
A line chart depicts changes over a period of time, showing data and trends.
A pie chart displays the size of each part as a percentage of a whole.
A (vertical or horizontal) bar chart is used to compare different items or phenomenons.
A flow chart is a diagram showing the progress of material through some steps.
A table is a convenient way to show large amount of data in a small space.
A population pyramid is a special kind of double histogram, that shows the structure of a certain population in one moment.
A map could also provide as many information as a chart or graph, showing a certain process distributed in the space, for example:
Besides, in this introductory paragraph we should name or mention the main topic or trend showed.
As we can see, in the last example, this world map shows/depicts/represents… the infant mortality rate in each country. There are a great number of verbs or sentences to express the main idea:
This graph shows, outlines, break out, list, ilustrates…
As an introduction of the firts example showed in this post, we could say:
This pie chart depicts the top 10 causes of death in the USA.
2. Description.
Afterward we should describe the trend or explain the differences depicted in the chart. The vocabulary depends on the type of graph we are commenting.
In a line graph we have to express the trend or tendency of each line.
If we have to indicate an upward movement, we can say:
raise, increase, progress, extend, expand, growth, reach a peak, …
If the upward tendency raises in a short period of time, we can describe it as: skyrocket, boom, jump, grow dramatically….
Subsequently, if we have to describe a downward tendency, we can say:
decrease, fall, sink, cut, drop, plunge, go down, decline… A very intense tendecy could be described as collapse or slump…
On the other side, the vocabulary used to describe lack of movement could be: remain stable/steady, keep the same, stay constant, stabilize, hold constant…
To describe the speed or degree of change, we can say:
dramatically, rapid(ly), quick(ly), sudden(ly), vast, huge(ly), significant(ly), considerably, moderate(ly), gradual(ly), gent(ly), slight(ly), slow(ly), quiet(ly)…
The commmentary of a pie chart should be completely different, as you must compare different slices or segments represented related with a topic. You have to express the magnitud of each slice:
the majority, a great percentage, more than 20%, a third/quarter of, a small minority, less than 10%, nearly the half/50%, a significant proportion, a very small number, almost a third…
In a bar graph commentary you should also compare different proportions or segment related with a certain topic. It’s very similar to the pie chart, as you must express porportions or fractions. But, very often you have to comment the evolution of this topic in time.