Collection of voting results at by-elections. Each constituency where by-elections have occurred also has the voting results for that constituency at the preceding general election and, where possible, at the subsequent general election Variables Votes received by Conservative, Labour, Liberal, Plaid Cymru and Scottish Nationalist candidates; total votes cast for all candidates; number of candidates, electorate, turnout for by-election and general elections before and after by-election. SPSS set-up deck calculates Steed, Butler and Gudgen swings between by-election and preceeding general election and between by-election and subsequent general election. No 1983 general election results are given for by-elections occuring between the 1979 General Election and December 1982.