The R number represents the number of individuals who, on average, will be infected by a single person with Covid-19.
We must be aware that COVID-19 is still a threat and we need everyone to play their part in helping to stop the virus spreading.
The R number can vary daily, but has been on the rise.
The Department of Health said: "When community transmission of the virus is very low, R will show a high degree of volatility and be heavily influenced by small local clusters".
"It will therefore no longer be the most informative or important number for the goal of policy decisions".
Visits to some care homes have been stopped amid concerns cases of Covid-19 are on the rise in Northern Ireland, prompting the Health Minister to warn we are at "one of the most risky phases" of the pandemic.
According to official figures, no further deaths have been recorded, leaving the death toll yesterday at 557.
A week ago, four people were admitted to hospital with Covid-19. Three are in intensive care.
Robin Swann said there had been 194 positive tests in the last seven days. This is partly due to increased testing in the context of the Test, Trace and Protect service. Six other care homes have suspected outbreaks.
In the Irish Republic, 92 more cases of Covid-19 were confirmed.
In total, the Public Health Agency (PHA) shows that since the start of contact tracing on 24 May, a total of 11 clusters have been identified in Northern Ireland.
In addition, there have been 20 clusters across Northern Ireland with fewer than five people.
These have been in the following council areas: Antrim and Newtownabbey Borough Council (1), Ards and North Down Borough Council (1), Armagh City, Banbridge and Craigavon Borough Council (1), Causeway Coast and Glens Borough Council (1), Mid and East Antrim Borough Council (3), and Newry, Mourne and Down District Council (4).
"It is very concerning that nine people have been admitted to hospital with Covid-19, two of which are now in ICU".
"I'm asking for people in Northern Ireland just to re-engage with the guidance that was put there, so we can prevent a serious increase in the number of cases in the coming weeks and months".
Key settings which have seen clusters to date since May include workplaces, retail or hospitality premises, domestic gatherings and sporting settings.
Dr Gerry Waldron, head of health protection at the PHA, said: "This disease has the potential to make its presence felt in any community, as we have seen with clusters appearing across a number of council districts".
Dr Waldron added that speculation around current clusters was not helpful.