The aim of the study is to assess learning and cognitive abilities, school performance, wellbeing and home and school environments so that we can understand the changing importance of the factors that influence development.

As the TEDS twins are in their final compulsory school year, this is a particularly important stage of the longitudinal TEDS project. Please contact us if you would like to find out more about TEDS or about this study.

• Parents log in to our web site, to fill in a consent form and to complete a brief questionnaire about your family background.
• Twins log in to complete a range of sixteen web activities, some of which are questionnaires and some of which are tests.
• In late August, we will send paper forms to collect the teenagers’ GCSE and other exam results.

Each online activity should take an average of around 8 minutes to complete. We expect that it will take approximately two hours for each twin to complete all 16 activities. There is no need to complete all the activities at once, and they can be done over several sessions on different days if that is preferred.

The parental consent form and questionnaire should only take one or two minutes. Filling in the GCSE exam results forms should only take a few minutes.

We plan to finish the current round of web activities at the end of December 2010.

We know that 16 year olds take a wide range of types of exams, including various vocational qualifications in addition to GCSEs. Using paper forms will allow the teenagers to record all types of exam results. This would be more difficult with an on line form, where we would probably have to concentrate just on the most common qualification types.

For the other activities, including our new questionnaires, we have been moving towards on line data collection for several years. This has several advantages, including a reduction in our costs, less impact on the environment through reduced use of paper, and improvements in data accuracy and security.

Before twins can take part, a parent must log in and complete the on line consent form. At the same time, they will be asked to complete our very brief questionnaire (5 questions) about your household.

Once the parental consent form has been completed, the twins’ logins will be activated. Each twin can then log in and start the online activities.

You will only be able to log in if we have asked you to take part in this study, in which case we will have sent you three sets of login details, one for a parent, and one each for the twins. If you have lost any of these, please simply contact us for a reminder.

The twin logins will not be activated until a parent has logged in and completed the on line consent form.

We will not change your login details midway through a study, so if you have been able to log in before then please try again. Type the details carefully without any spaces – it should not matter whether you use lower case or capital letters.

Yes, the web activities should work correctly in most up-to-date web browsers: Internet Explorer (version 6 or later), Safari (any recent version), Firefox (version 2 or later) and Google Chrome. The latest versions of these browsers are easy to download and install from the web:

• Mozilla Firefox – from http://www.mozilla.com/firefox/
• Google Chrome – from http://www.google.com/chrome
• Apple Safari - from http://www.apple.com/safari/
• Microsoft Internet Explorer 8 - from http://www.microsoft.com/uk/IE8/

Some of the web activities use software called Flash for animations and other interactive content. The activities may not work correctly if you do not have an up-to-date version of Flash installed for your web browser. To fix this, install Flash from http://get.adobe.com/flashplayer/. This process is quite fast, and should take less than a minute.

There may be a particular problem with your computer. Sometimes re-starting your computer can help. Or try a different computer, if you have access to one.

There may also be a problem with your internet connection. Try other web sites – do you have problems with these as well? These are sometimes temporary local problems, and if you try again later you may find that the problem has gone. If you have repeated problems with your connection, you should contact your internet provider.

The problem may be related to the browser you are using – try using an alternative web browser, or try re-installing Flash, as described under the headings above.

Finally, if none of the above suggestions work, contact us and ask for help.

For the twin questionnaire activities, the answer is yes. Read-only versions of these questionnaires can be viewed by parents after logging in (follow the link to the information sheet).

However, for the test activities the answer is no. To make these tests fair, we allow each teenager to see and attempt each question only once.

For questionnaire activities, the answer is no, especially in sections involving more personal questions. Teenagers will be able to choose to leave some questions unanswered.

However, for the test activities the answer is yes: every question must be attempted so we can make a proper assessment of the teenager’s abilities. Most questions have multiple choice answers, so if your teenager is stuck then they can make a guess at the answer.

Firstly, each twin will receive a £10 voucher on completion of all the web activities. There is a choice of either iTunes or Love2Shop vouchers.

Secondly, we will be holding a prize draw each month (from September to December) for all teenagers who have completed some of the web activities. The dates of the prize draws will be advertised on our website. There will be 30 prizes each month including iPads, iPods, and iTunes vouchers worth £50 and £25.

Each twin will receive one prize draw entry for every activity they have completed so far; they will also receive a bonus entry to the prize draw once they have completed all of the web activities. Prize draw entries are carried forward to all the remaining draws.

For example, a teenager who has completed 8 of the activities by the first prize draw date will be given 8 entries in the draw; if no more activities are completed, then s/he will still have 8 entries in the following draws as well. If the same teenager has completed all 16 activities by the second prize draw date, then s/he will have 17 entries (1 per activity plus 1 bonus entry for finishing) in the second, third and final prize draws. So the sooner the activities are completed, the more chance there is of winning a prize in the draws.

In each draw, winners will be picked at random from the pool of entries. In each case, the same prize will be awarded both to the drawn teenager and to their twin. The first winner (and their twin) will receive an iPad, the next two winners (and their twins) will receive iPods, and so on.

The findings will be published in scientific journals, and also made available on our web site after the completion of the study. As always, information provided by your family will be kept strictly confidential and anonymous.

When you log in to complete the web activities, your details are encrypted so they are securely transmitted over the internet. All the data that you submit are stored safely in a database on a secure server, which is located in the TEDS office. Only authorized TEDS research staff have access to the data.

All the data provided by your family are strictly confidential; your twins are identified only by a number in the study datasets. The data will be kept for a minimum of 10 years after completion of the TEDS study, as recommended by our funding body the Medical Research Council (MRC). The TEDS data are sometimes shared with other researchers, but only after removing identifying information about the participants. We will not pass your family’s information on to any other organisations. You are free to opt out of the study at any stage without giving a reason; data already collected will be stored anonymously, but no further data will be collected.

It is up to you as a family to decide whether or not to take part. If you do take part you are free to withdraw at any time, without giving a reason. Your decision not to take part in this study will not affect your involvement with TEDS in the future.