Teenagers and their sleepless lives
Teenagers have never been so tapped into technology - but how much is it taking over their lives? As part of BBC School Report's News Day, three teenagers describe the impact technology and social media have on their sleep, relationships and free time.
Heather, 15, Priory School and Specialist Sports College, Portsmouth
I'm on Facebook every day, probably for between one and three hours - but that's probably a lot less than some of my friends.
Sometimes you see online arguments blow up on Facebook and go on and on, and I just think to myself "How do you have enough time to spend on here arguing?"
I think in some cases social media does make teenagers less active.
But if I'd been born 30 years ago, and there wasn't social media and technology around everywhere, I still wouldn't have done any more sport. I'd have probably just been in the library a lot more.
In the evenings, I'm often in my bedroom using my laptop to revise using BBC Bitesize or finding old exam papers. But I usually have other tabs with social media or other websites running, and it's very tempting to just give yourself a few minutes off to check on those.
I think being online in bed is very different to reading a book. Being online is a lot more interactive and stimulates your brain in a different way, but I think I actually prefer books.
My parents trust me to manage my time online, and I try to finish by 11.30 at night, but it's very easy to lose track of time and suddenly realise it's way past then. But that can happen reading a book too.
I don't think what phone I've got is an issue for me. Half the time my phone doesn't have credit, and if I'm just calling my parents to tell them where I am, that can be done on my old "brick".
If anything, my dad - who's 47 - is more competitive about having the latest technology than I am. He gets really excited about having a new phone, and I just tend to wonder what does it really do that the last one didn't.
I do think that having brand-new phones is an issue for safety, but a lot of my friends tend to plan ahead and leave expensive things at home if they're going somewhere they think is risky.
My friend was pick-pocketed on a school trip to Germany and had her money stolen, but she'd deliberately left her phone in her room.
Sadia, 11, Our Lady's Convent High School, Hackney
I've got a laptop, a TV and an iPod Touch in my bedroom and I also have a Blackberry, which is one of the old ones.
When I go to bed and I'm supposed to be asleep, I sometimes talk to friends online or text them but it doesn't really affect my sleep because I like to wake up early. Sometimes I might read a book at night. I like doing both, because reading a book gives you education, and going online means you can talk to family members abroad and stuff like that.
I usually have four hours to go online and at about 6pm, my mum says I have got to read a book. Then I watch TV and go to bed, but sometimes I bring my iPod with me and listen to some music.
Modern technology does stop you playing outside so much because it's really addictive. Sometimes when I'm doing my homework, I just get carried away with talking to my friends online but my mum comes and tells me when it's time to stop.
I don't really have time to always see my friends face to face, so I'd rather message them - but we definitely have more fun when we meet up.
Olivia, 14, Tarporley High School, Cheshire
Your phone becomes a statement - you have to be able to access your social media on your phone, otherwise you can't stay in touch with what's going on.
And you really notice that lots of people's profile pictures show them holding their smartphone or looking into the mirror with their phone in hand - it's almost like the phone is part of them.
There is a hierarchy of the different brands of phone, and people who don't have a decent phone would probably be teased at least a little bit. I think you'd have to learn to laugh at yourself a bit, to be honest.
Sometimes I look at my friends' phones and think "I want that". I think lots of teenagers think that way too.
I'm unusual in that I'm not on Facebook, but I do like using Twitter and my mum and my auntie are on there too. I think that makes me self-censor what I write, but that's probably a good thing.
I think they feel I'm mature enough to deal with social media pretty responsibly. But if I was to tweet something inappropriate, I know it would be that would have to face up the consequences.
I tend to count to 10 before I tweet, as sometimes arguments happen on social media and get blown out of all proportion.
I often find myself thinking "why are you tweeting this?" The things that some people want to share - effectively with the whole world - could have a big impact on the rest of their life, for things like finding a job in the future.
I'm actually very disciplined, but I think the older you get, the longer you will probably end up staying up for, as that's when you spend more of your time online. If you're multi-tasking by tweeting when you're watching a soap earlier in the evening, that's different to being on Facebook or Twitter later on in your room.
I see a lot of people tweeting "I can't sleep" late at night or in the early hours. It shows you that people really are just spending their time on their phones, but sometimes I wonder why they want to share that information with me.
I don't have a curfew set by parents as such, but I think that I kind of have one anyway that I impose on myself.
The problem with being online late at night - rather than reading a book or something - is that there's always more to read or find out about. Teenagers are naturally curious and if you see something someone has retweeted, you want to click on their profile to see who they are. And then you find more things to click on, and so on - it's never ending. For some people, their phone is like another limb. They really can't be without it.
I like to think I don't fit the anti-social teenager stereotype - I'm just as happy talking to people face-to-face socially, not hiding away behind a screen.