"One [reason] is that the surveys were a year and a half apart – there could have been some change over time. A second is that the BBC gave different response options, including immigration should be stopped completely – which can change the distribution of responses," Blinder said.
The BBC poll showed 38 percent of Scots thought immigration to the UK had been negative compared to 27 percent who thought it had been positive.
In February 2014 the Migration Observatory found 41 percent of Scots thought immigration was good for the economy, with 31 percent believing it was bad.
The Migration Observatory's former director told Sputnik a third factor that may result in different findings over the past year may result from the random nature of polling generally.
"Finally, it is important to note that context matters. The [news] stories that frame the debate at the time when the poll is undertaken can affect people's responses," Blinder said.
The issue of immigration is expected to play a prominent role in the forthcoming UK General Election that is due to take place May 7.
The anti-immigration UK Independence Party party won its first elected member in Scotland in European elections held last May, but the Scottish National Party currently has control of the Scottish Government and a majority in the Scottish Parliament supports increased levels of immigration to Scotland.
