How can I maximize my focus during a one and a half hour class?

Turn your phone off and put it inside your bag. No, seriously. Your snapchat/whatsapp/tweet/text can wait. Nothing, I repeat nothing is more important than what's happening inside your classroom for which you're probably paying a lot of money. Would you pay me money if I let you sit in my living room for one hour everyday which you can spend checking your phone? Sounds ridiculous, right? Why would you do that in the classroom? Develop the habit of taking notes. Take a water bottle with you. Every time you feel like checking your phone, take a sip of water and get back to paying attention to the professor. Sit as close to the professor as possible, that way you'll at least feel awkward about using the phone very often. You have said the courses are hard. That's all the more reason for you to pay attention to the class instead of checking your phone. Checking the phone once or twice is fine, but I don't think you should be taking that chance either. I repeat, silence it/switch it off and put it inside your bag. If you think the professor isn't being clear or you're not benefiting from attending the class, skip them. Study the material by yourself.

In addition to the good advice already offered here, I'll suggest a bit of caffeine about an hour before class. Not a lot. Not enough to buzz you. You'll have to experiment a bit to see how much works for you. Regarding your phone: imagine holding it in your hand and watching it grow bigger and bigger and bigger until it's so big you're worried it'll fall over on you. Try really hard to hold it up.

You didn't tell us what sort of class, your educational level or your age, but let's assume it's a sitdown lecture in some sort of high school or college. Do you have sufficient motivation for being in the class or that college in the first place? If no, sort that out. If you're not serious about studying and you're just running up debts and getting a bad GPA, you're wasting your life. Sort your head out. So: the phone distraction. Unless you have a child/dependent/relative who might need to urgently message you (99% of people don't; if you're in the 1%, then assign them a different ringtone), or you think your text life is more important than your education, you should turn it to silent for the entire class. Really you probably have no reason to bring it into class. Certainly no IMs, no FB, no Twitter, no surfing, no sending/viewing pictures. If your willpower sucks (and to be honest, we all have our weaknesses), then either leave the phone in your locker, turn it off, totally uninstall the attention-sapping apps, or use a blocker or monitor as per other answers here. Tell all your friends your busy-time schedule and not to message you then, or that you won't respond between 9am-2pm on Mon-Thu. Pick the friends who are the worst repeat offenders and tell them in person. Or block them. Pick a week and challenge all your friends to go cold turkey without messaging you. Install a productivity app or blocker software to restrict you using (say) IM+FB+Twitter+Snapchat+Instagram between say 8:50am-12pm. Or at least to monitor your use and tell you when you're overdoing it. Ok here's a compromise technique to motivate/bribe/control/redirect your phone urges. When you get the urge to use it, close your notes and give yourself a pop-quiz: can you state what the points from the last 10 minutes were? If yes, you can use the phone. If no, you weren't paying attention, no phone for you. How easy or hard is the subject, and your knowledge of it? If you can get an A+ without attending and get no benefit from classes, then you might not need to attend lectures (if this is college). But that's generally a bad idea. Lecturers place value on attendance, quizzes, tests; also it's really helpful to know your classmates. Sometimes the camaraderie will pull you through, or give you useful information esp. around exam time. How is the pacing of the class and the lecturer style? Slow? Fast? Unpredictable? Dry boring monologue? Snoozefest? Socratic method? Group discussion? Videos? Do they give handouts? You can either do your best to adapt to their style, or make some suggestions (constructively-phrased) to the lecturer about changing the format (if they're approachable - some appreciate that, some hate you). Take notes. Structure your notes, summarize, condense constantly, while the class is in progress. Use 100% of your brain. Use different colored pens for sections and highlighting. Put a summary box around the main points from the class. (If you don't know what they were, that will motivate you to ask the lecturer, or at least your fellow students. Or read the textbook. Read slightly ahead of class, if that helps.) Form a study group: 2-5 people, no timewasters, kick out anyone who tries to free-ride. Meet regularly and summarize the material back to each other, discuss homework (as allowed) etc. Pick people whose styles, schedules and commutes are compatible with yours (you can even discuss stuff while ridesharing). This is really helpful for motivation and keeps you on track and accountable. Also makes heavy workloads or reading-loads manageable. Ninety minutes is long to concentrate, especially with a bad lecturer on a boring subject. Sometimes lecturers will give a 2-5 min break to get coffee, stretch your feet, go to the bathroom, chat to your neighbors. It helps break the monotony. You could suggest it (through your class representative, if in college). In the extreme case, when I was at college, if I was at a really boring lecture (which was often), just walk out and get a soda or a coffee, and come back 2 min later (if this is allowed). Or you could bring snacks and eat them at the 45-minute point. Peanuts, raisins, PB&J sandwich, energy bar, fruit, avoid junkfood. If you keep losing concentration at the same time of day, then look into your nutrition, exercise, go for a walk.

Well, you need to switch off the phone indeed.  In China, sometimes we call cell phone as dog chain. people pull it as though you were dog. of course, they don't mean it. By focusing you mean improving efficiency. they are something pretty much different. Smart asses usually improve efficiency as much as possible by a tool box instead, When they attend a class, they play with their tool box in compassion as though they were focusing pretty much.  because ability of focusing depends largely on gene and for an educated people 40 minutes maximum.

1. Eat Tuna for breakfast or lunch, because Tuna has been proven to boost concentration. 2. When in class, turn your phone off, and consciously try to focus on the class alone.

Can listen to Les Brown on youtube one video in particular is "You Gotta be hungry " Think of that one and half hour class to be the last class before your exam. Your phone is your weakness as you have let it to be , make it strength how? Just like you would not use your toothbrush unnecessarily , you would not speed your car while approaching red lights on street , you would not go out of your home after 12 o clock at night those all things are learned by you even not knowing. My Favourite Qoute : "By Yard its Hard but inch by inch anything is possible" If you like what you read and you feel like appreciating it then visit the links below: http://haqbahu.com/ http://hazratsultanbahu.com/ http://revisebook.com/

Classes are only a tool to help you learn better. I assume your primary goal ( and the goal of your schooling) is to learn how to become an adept programmer. So if the class is truly helpful, then focus on what you can get out of it and you will naturally pay attention. If it isn't, then don't pay attention and bring other work or resources that are more helpful for your goal, because remember, all this energy put into learning is to improve our skills. If the class doesn't help, we should find other resources that are more helpful to us. Hope this helps!