Dear Karen, I don't have much data for half-siblings and the other relationships you mention. In any case, you simply cut in half the percentage you would have for full relationships. For instance, half-siblings should in theory share about 25% of their autosomal DNA and half-first cousins should share about 6.25% of their autosomal DNA. Sincerely, Tim Janzen -----Original Message----- From: autosomal-dna-bounces@rootsweb.com [mailto:autosomal-dna-bounces@rootsweb.com] On Behalf Of Karen Hodges Sent: Sunday, October 06, 2013 4:09 PM To: autosomal-dna@rootsweb.com Subject: Re: [AUTOSOMAL-DNA] once removed etc. Hi Tim I found the link very helpful but noticed for close relatives there was no inclusion of half siblings, half Uncles and Aunts or Half nephews or nieces and half first cousins. Is it a matter of just halving full numbers? Karen