``We'll never know if we've stopped someone from having to go through that, but that's our aim,'' he told the Herald.
``If we can just stop one person ... Just to stop one family having to go through what we've all been through - it's definitely worthwhile.''
The Longleys' plan follows the launch of a safety campaign in Emily's honour at the school she was attending in the UK.
Brockenhurst College said the aim of the week-long All-Ways Safe scheme was to teach students how to stay safe in a variety of situations in a bid to prevent a repeat of what happened to Emily.
The campaign would cover a variety of topics including personal safety, relationship safety, road safety and cyber safety.
Police, victim support, firefighters and other agencies will visit students to spread the message ``Be safe, not sorry''.
``We have a duty to our students to ensure that they remain safe not only on our campus but in the wider world,'' principal Di Roberts told Bournemouth's Daily Echo newspaper.
``Our All-Ways Safe week gives us the opportunity to ensure that they are aware of a range of safety issues that might affect them and to encourage them to take necessary steps to safeguard themselves and others.''
Mr Longley said the scheme was fantastic.
``I think anything like this is really positive and one of the things that has dawned on us throughout Emily's case and subsequently is that there's a lack of education, particularly on domestic violence.
`Something like that would be the ultimate aim but we're starting smaller. I don't want to go into too much because it's still in the very early stages, but it's our plan to at least talk to school-age kids and relay Emily's story to them and try to raise awareness around domestic violence.
``I think that was the case with Emily. It was so far removed from her reality that I don't think for a minute she thought her life was in danger.''
Mr Longley said Emily's death was still very hard to accept.
``We're getting on with our day-to-day lives okay, but we're still deeply mourning the loss of Emily.
``It's a long process that doesn't seem to be getting any easier as time goes by.''