NovHow I decide that a source is too old for the claim
Ekaterina Andreeva on source age: when old evidence remains useful and when it can no longer support a current price, rule or project status.
This article reflects the named expert’s practical perspective. See NovAsia’s editorial policy for how material is prepared and reviewed.
An old source is not automatically a bad source. The question is whether we are asking it to prove something that could have changed.
Last year’s price list is useful for price history. It is weak evidence for the sentence “this is the current price.” A market report can explain an earlier cycle without describing demand today. A legal instrument may remain current for years unless it has been amended or replaced.
So I do not give every source the same expiry date.
Source age only becomes meaningful when it is tied to the volatility of the fact. Availability can change quickly. Construction status moves on a different schedule. Annual market statistics are historical by design. A research methodology can remain relevant for years. A legal rule may be stable for a long time and then become outdated the moment an amendment takes effect. One universal freshness threshold would treat all of those facts as if they behaved the same way.
The more useful question is: what could have changed since this was published? That question shifts the review from calendar age to decision risk. If the fact is a current price, a recent check matters. If the claim explains how an index is calculated, an older methodological note may still be the best primary source. If the article relies on a legal provision, the task is to establish whether it remains in force, not to find the newest blog post about it.
Prices, availability and construction status need recent checks. A research methodology can remain relevant much longer. You can see that distinction throughout the NovAsia project catalogue: a page can contain facts with different verification dates because those facts change at different speeds.
Wording determines freshness requirements too. “The unit was advertised at $X in March” is a historical claim that a March price list can support perfectly well. “The unit costs $X” is a current claim and asks more of the same document. The source has not become worse; the sentence has changed the job it is being asked to perform.
Market reports add a second date problem: publication date and observation period are not the same. A report released this month may analyse the previous quarter or year. It can be the newest available report and still describe older market conditions. That is not a defect if the period is visible. It becomes misleading only when a recent publication date is allowed to make the underlying observations look current.
Legal sources often work in the opposite direction. An older statute or regulation may still be authoritative, while a newer article can be wrong because it relies on a superseded interpretation. Here, I want to know whether there have been amendments, replacement instruments or official guidance that changes how the rule applies.
Before publication I ask what could realistically have changed since the source was issued, and whether a newer source of comparable quality exists.
The phrase “comparable quality” matters. A recent unsourced blog is not automatically better than an older primary document. At the same time, an old primary document should not be treated as current if an updated official version exists. Freshness and authority have to be considered together.
Web pages create another complication because their visible update date may not belong to the specific fact we use. A page can receive a new layout, image or disclaimer while the price table remains untouched. I do not want a fresh page timestamp to silently refresh every statement inside it.
There is also value in keeping older sources when the article is explaining change over time. Historical price lists, earlier project timetables and past market reports help establish a sequence. The solution is not to purge them from current pages, but to label their role. History should look like history; current status should have current support.
If no newer evidence can be found, the honest answer may simply be: this is the latest information we located, dated X. That is more useful than refreshing the page timestamp and leaving an old fact looking current.
I avoid turning that sentence into a generic disclaimer. The date should appear where it helps interpret the claim. A reader deciding whether a unit is available needs a different freshness signal from a reader trying to understand how a market behaved two years ago.
For me, a source becomes “too old” only in relation to the claim. A decade-old methodological document may still be foundational. A week-old inventory snapshot may already need another check. Editorial freshness is not a fixed number of days; it is a judgement about how quickly the underlying fact can move and how much the reader’s decision depends on it.