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APPENDIX 1
THE SAMPLE

The aim in this inquiry was to obtain a representative sample of 3,260 civilian adults (aged sixteen years and upwards) in Great Britain.

THE METHOD

The total of 3,260 interviews was first allocated to the twelve Civil Defence regions on the basis of the Registrar General's population figures. Then within each region the correct proportion of interviews was allotted to urban and rural administrative districts. The rural interviews were allotted to one or more districts chosen at random and the urban interviews were distributed by grouping the towns of the region by size, allocating the correct proportion to each group and then choosing a town or towns to represent that group, A list of the districts in which interviews were made is given below:

NORTH

Sunderland

Stanley

Redcar

Morpeth R.D.

EAST

Norwich

Bedford

Wisbech

Samford R.D.

SOUTH WEST

Bristol

Exeter

Totnes

Bradford and Melksham R.D.

Stroud R.R.

NORTH WEST

Manchester

Birkenhead

Oldham

Crewe

Bootle

Lytham St. Annes

Runcorn

Winsford

Clitheroe

Penrith R.D.

NORTH EAST

Sheffield

Bradford

Huddersfield

Bridlington

Saddleworth

Flaxton R.D.

LONDON

St. Marylebone

West Ham

Hampstead

Uxbridge

Tottenham

Woolwich

Mitcham

WALES

Cardiff

Neath

Pontadawe R.D.

Wrexham

SCOTLAND

Glasgow

Motherwell

Falkirk

Arbroath

Kinross County

NORTH MIDLANDS

Nottingham

Northampton

Cleethorpes

East Retford

Blaby R.D.

SOUTH

Bournemouth

Slough

Ryde

Aylesbury R.D.

MIDLANDS

Birmingham

Coventry

Smethwick

Burton-on-Trent

Halesowen

Warwick

Hartley R.D.

SOUTH EAST

Gillingham

Margate

Chichester

Godstone R.D.

To obtain the necessary names and addresses the adult portion of the Maintenance Register in each of the chosen districts was used. Addresses were drawn at equal intervals through the register to form a main list of names. A shorter list of addresses was prepared in a similar way to provide substitutes for any members of the main list who could not be interviewed.

The interviewer was instructed to return a schedule to every name on the main list. Whenever she failed, after at least two recalls, to interview a person on the main list as much information as possible was collected about that person so as to judge the effect on the final sample of the failure to make contact and a substitute was then interviewed.

THE RESULTING SAMPLE

Of the total number of 3260 interviews set, 3,137 (96%) were completed by the end of the survey and of these 496 (16%) were substitutes. An analysis of the reasons for taking these 16% of substitutes is given below:-

Clearly the sample should not contain those persons who are dead, in the Forces, or have moved to other districts (these latter will appear in other registers) and it is necessary to substitute for these. This accounts for 7 out of the 16%.

For the remaining 9% (274 persons) an attempt has been made to classify them on the basis of what information could be collected. For example the ages of 206 (75%) of these 274 people were obtained and a comparison of their age distribution with the Registrar General’s figures shows no significant difference.

The marital status of 226 (83%) of the 274 non-contacts was obtained and this shows a slightly lower proportion of married people among the uncontacted.

In education and occupation there was no significant difference between the uncontacted persons and the total sample except that there was a slightly higher proportion of retired and unoccupied among the non-contacts.

This analysis suggests that substitution for the 9% uncontacted persons has had little effect on the representativeness of the sample.

It is interesting to note that only 2% of the sample refused to be interviewed.

Some further analyses and comparisons of the sample follow:

All the evidence suggests that this is a representative sample.