Reading Spanish Charts, Tables, and Survey Findings

In this lesson, you will read a chart or table by checking its title, axes, units, scale, legend, and stated sample size before drawing conclusions. You will identify trends, exceptions, and valid comparisons, while keeping description separate from explanation.

Start with the title

Example title:

— Weekly public-transport use by age group.

The title tells you what the visual is about, but not yet how the data were collected.

Check the unit

— Unit: percentage of respondents.

This means the bars represent proportions, not absolute numbers of people.

Check the sample size

— Sample: 600 residents.

A sample size helps you understand the scale of the survey, but it does not by itself prove that the sample represents an entire population.

Read the table

Grupo de edad	Usa transporte público al menos 3 días por semana
18–29	68 %
30–44	55 %
45–64	41 %
65+	47 %

Identify the main trend

— Use decreases across the 18–29, 30–44, and 45–64 age groups.

Identify the exception

— The 65-and-over group breaks the downward trend, at 47%.

The value rises relative to the 45–64 group.

Make a valid category comparison

— The 18–29 group exceeds the 45–64 group by 27 percentage points.

Do not invent absolute counts

If the visual gives only percentages and does not state how many respondents were in each age group, you cannot calculate the exact number of users in each category.

Unsupported:

— 408 young people use public transport at least three days per week.

The total sample is 600, but the size of the 18–29 subgroup is not given.

Check the scale

If a vertical axis begins at 40 rather than 0, small differences can look visually larger.

— The scale can make a small difference appear larger.

Check the legend

Legend example:

— blue: 2025; gray: 2024.

Without reading the legend, you can easily reverse the years.

Description is not explanation

Description:

— The percentage for the 18–29 group is higher than that for the 30–44 group.

Unsupported causal explanation:

— Young people use public transport more because they own fewer cars.

The table does not provide car-ownership data, so that cause is not established.

Correlation is not automatic causation

If a chart shows that neighborhoods with more bike lanes also have more cyclists, you can say:

— There is an association between more bike lanes and greater bicycle use in the data presented.

You cannot conclude from that relationship alone:

— Bike lanes caused the entire increase in bicycle use.

Check the survey wording

Question:

— Do you use public transport at least three days per week?

This does not measure total journeys, satisfaction, or reasons for travel.

Limit the generalization

Accurate:

— In this sample, the 18–29 group has the highest percentage.

Too broad:

— All young people in the city use public transport more.

Short chart-reading summary

— The chart shows the percentage of respondents who use public transport at least three days per week. The 18–29 group records the highest value, at 68%, and the 45–64 group the lowest, at 41%. The 65-and-over group is an exception to the downward trend because it rises to 47%. The data allow these differences to be described, but they do not by themselves explain their causes.

A practical chart-reading method

Read the title.
Check axes, units, scale, and legend.
Note the stated sample size and what is not stated.
Identify the main trend and any exception.
Make only comparisons supported by the visual.
Separate description from causal explanation.
Do not turn a correlation into confirmed causation.
Limit generalizations to the population and sample actually described.

From Charts to Technology and Privacy

You can now interpret a chart or table within its stated limits. The next lesson develops vocabulary for discussing technology, privacy, and everyday trade-offs.