Frequency, Tabulation and Graphical Presentation

Frequency is a summary measure that describes both categorical and quantitative data. It counts the number of times a category or a data value is repeated. The summary data can be presented in tables and graphs. I exemplify from the database on COVID-19 incidence and human death worldwide as of April 28, 2020, which I downloaded from the European Centre for Disease Prevention and Control website.

Categorical Data

I was curious to know how many countries in different continents or regions had had deaths.  I found that 169 out of 206 countries had deaths and 37 did not deaths as shown in Table 1. Most European countries had deaths and most African countries did not have deaths.

Table 1: Countries Reporting Death Due to COVID-19

Above data can be visualized in a bar chart for better presentation as shown in Figure 1.

Quantitative Data

I was curious to know how many countries had how many numbers of death due to COVID-19 falling in a certain class interval. I found that most countries (161 out of 169) reporting death had deaths falling within a class interval of one to less than 5000.  It was followed by three countries that had deaths in the interval between 5,000 to less than 10,000. One country had deaths within the range of 55,000 to less than 60,000 (Table 2).

Table 2: Country and Death Due to COVID-19

The above data can be presented in the histogram as shown in Figure 2. Data shows that the number of countries is positively skewed.

I was curious to know how many persons died at what time interval. It was appraised that in April 2020 alone 82 percent of total 209,776 people died. It seems that the number of deaths is rapidly increasing by the month. It could be because people who suffered in initial months started to die.

Table 3: Death by Month in 2020

Above data can also be visualized in the Time series line chart in Figure 3. 

In a nutshell, frequency is a process of summarizing data, which can be presented in tabular and graphical forms.