TEDS Data Dictionary

1st Contact Data Returns

Most of the figures in the table below are based on information logged in the TEDS admin database. However, figures for 'data in the dataset' are based on the final analysis dataset itself. Discrepancies between returns and actual data arise because of logging errors, unusable data, and losses of data.

The figures shown in the table below are numbers of families (twin pairs).

Cohort (birth year of twins):	1994	1995	1996	TOTAL
Original ONS sample:	5640	5710	5460	16810
1st Contact booklets sent	5406	5535	5362	16303
1st Contact booklets returned by 1999:	4759	4678	3712	13149
Percentage of booklets returned by 1999:	88.0%	84.5%	69.2%	80.7%
1st Contact booklets returned since 1999 *:	86	136	388	610
Total 1st Contact booklets returned:	4845	4814	4100	13759
Overall percentage returns:	89.6%	87.0%	76.5%	84.4%
Data in the dataset	4839	4801	4082	13722

* includes the 'You and Your Family' booklets sent in 2000-01, data collected by phone in 2004-06, and shortened booklets sent in 2013.