TEDS Data Dictionary

3 Year Data Returns

This page summarises data returns in the 3 Year booklet study.

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). Note that families in the 1996 cohort were not contacted for this study.

Cohort (birth year of twins):	1994	1995	TOTAL
Original ONS sample	5640	5710	11350
3 Year booklets sent	4666	4684	9350
3 Year booklets returned	3122	2997	6119
Percentage of booklets returned	66.9%	64.0%	65.4%
Data in the dataset	3095	2964	6059