Start here · Essential guide
How Trend Data Is Collected and What Each Source Misses
A plain map of the main ways trend evidence is gathered, from surveys to platform logs and sales records, and the blind spot each method typically carries.
Evidence and Method
How Trend Data Is Collected
Where the numbers behind trend stories come from and what each source misses.
How Question Wording Changes Survey Answers
Phrasing, question order and answer options can steer survey responses. Plain examples show how small wording shifts can change what a poll appears to find.
How Sales and Transaction Records Describe Trends
Purchase data can show what people actually buy, but not why they buy or what non-buyers do. Learn what transaction records reveal and where they fall short.
How Survey Panels Work and Who They Leave Out
Survey panels are groups of people recruited to answer questions repeatedly. Learn how panels are built and kept up, and which people typically go missing.
Platform Data and Its Blind Spots
Data from social platforms offers scale but covers only certain users and activity. See who is invisible in it and why access rules limit outside checking.
Self-Reported Behaviour Versus Observed Behaviour
What people say they do and what records show often differ. Learn why that gap arises, when each kind of evidence helps, and why it matters for trend claims.
What Search Interest Charts Do and Do Not Measure
Search interest charts show relative curiosity over time, not adoption or popularity. Learn how scaling, sampling and news spikes affect how to read them.
Why Sampling Decides What a Trend Appears to Be
The list a sample is drawn from limits what a study can find. See how sampling frames shape apparent trends and why coverage matters more than sample size.
Related topics