Becoming a Better Data Citizen. Beyond the Percentages -Assessing True Prevalence in Data

Listen to AI Narration

0:00

/354.288

1×

Statistics are often presented suggesting one group exhibits higher or lower rates of some trait compared to another group. This data may come from news headlines, reports in the workplace, research findings, or other sources. Yet without scrutinizing the underlying numbers, data citizens risk developing misguided perceptions no matter the source. Becoming a better data citizen means looking past surface-level percentages to truly understand absolute prevalence, while also questioning standalone statistics to ensure proper denominators are considered. Evaluating figures in context rather than isolation allows for the discernment of credible insights versus misleading portrayals.

Understanding Key Data Terminology

When evaluating data comparisons, it’s important to understand key terminology related to reporting formats:

• Prevalence refers to how frequent or widespread something is in terms of total cases or frequency within a population. Synonyms like absolute count, total quantity, and overall magnitude also describe prevalence. This data format communicates the comprehensive size of a phenomenon.
• Percentage represents a proportional rate - a part-to-whole relationship describing what portion of the population exhibits a specific trait. Percentages quantify the relative scale but exclude the sample size context.

Examples

Suppose a report claims that 50% of products sold by Company A receive 5-star customer ratings, while just 40% of Company B's products get 5 stars. This makes it sound like Company A has higher quality merchandise.

However, the underlying sample groups differ - Company A only sells 10 products whereas Company B sells 100 different products. So breaking it down:

• Company A has 5 products rated 5-stars (50% of 10 products)
• Company B has 40 products rated 5-stars (40% of 100 products)

While the percentage is lower, the absolute number of highly rated products at Company B is much greater at 40 items versus 5 at Company A. But looking strictly at the percentages obscured that nuance.