To Fintan Mullan, the best way to trace one's Irish roots is to travel to the Emerald Isle.
''There is so much offline that you have to look through in the archives yourself,'' said Mr. Mullan, director of the Ulster Historical Foundation based in that Irish city.
"You can build a rudimentary family tree from online information, but only by coming here can you get a sense of the culture and traditions and how close they all lived to one another. ''You will want to stand at a grave and say a prayer and see the family farm,'' he said. "You can't do that remotely, even with digital maps,'' he said.
For Americans who cannot visit Ireland, Mr. Mullan and the foundation's research officer, Gillian Hunt, will be embarking this week on a 10-city U.S. tour to show how to investigate genealogy from the comfort of home.
From 1 to 4 p.m. on March 20, the duo will present, ''Tracing Your Irish and Scots-Irish Ancestors'' at the Westmoreland County Historical Society's Calvin E. Pollins Library, 362 Sand Hills Road, Suite 1, Greensburg. This will be the second consecutive year for the presentation, which sold out last year.
The Ulster Foundation is a nonprofit founded in 1956 to promote interest in Irish genealogy and history, with particular reference to the nine-county province of Ulster, the northern most province of Ireland.
But the resources discussed will be applicable to all 32 counties, Mr. Mullan said.
Topics will include: an introduction to Irish and Scots-Irish family history research; understanding Irish towns; using land valuation records; and an extended question-and-answer session in which speakers use online resources and their local knowledge to offer practical tips about Irish and Scots-Irish research.
Mr. Mullan said many resources are available online, such as the 1911 and 1901 censuses, with the latter the first complete surviving census.
The 19th century census returns do not exist because they were destroyed by government order [they were considered unnecessary] or in a fire in Ireland's main courts building at the start of the Irish Civil War in 1922.
To compensate for the missing information, genealogists search land valuation records, such as Griffith's Valuation completed in 1868, for tax maps, defaulters' lists, deeds, and more. A good source for Griffith's www.askaboutireland.ie .
For searches before Griffith's, there are the Tithe Applotment books, a computation of the value placed on the land of a farmer and the resultant tithe payable to the local parish.
''Everyone had to pay a tithe even if they did not belong to the Church of Ireland'' Mr. Mullan said.
While all the books are available in the National Archives of Ireland, books for 26 counties can be found at:
But Mr. Mullan said the most important resource is www.rootsireland.ie, Ireland's largest family records database, with about 20 million records of marriages, baptisms, burials and more.
''If you were looking for a marriage but did not know the location, you can still find the marriage.
''If you know where your ancestor comes from you can go back generations for all sorts of information as Irish families had a tendency to stay put,'' Mr. Mullan said.
The library fee, which includes materials, is $25 for WCHS members; $30 for others. Space is limited and reservations are required by March 17. Call 724-532-1935 ext. 210.
Margaret Smykla, freelance writer: email@example.com.