Tips & Tricks for K-12 Educational LANs

• 04/01/96

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For the past several years, I've been employed as a computer technician in an elementary school and worked with my district's administration to develop the labs in our schools into functional computer learning centers. Along the way, I've developed a good grasp of what has worked and what could be improved. For those districts planning to add computer technology to their instruction, these suggestions and ideas are offered as a guide.

Some Hardware Basics

Let's start with some basics. Use multiple circuits for the lab. If you have a lot of computers you'll need to distribute the load on the circuit breakers. Consider having three separate circuits. One for the monitors (shut off the monitors to get children's attention or clear the room at the end of class), one for computers (start up the lab with the flip of a switch), and one for things that should never be turned off like the file server and printers.

To do this you'll need to know the amount of electricity that the computers will draw. It will be expressed in a figure called amps and is often on the back or bottom of equipment. When in doubt, check with the manufacturer. Always round this figure up. For example, if the computer, monitor and CD-ROM drive together draw 4.3 amps, round up to 5 amps.

Place wires and power cords on the back side of computer tables, not along the ledges. Small children, whose feet won't reach the floor, like to prop them up on those ledges. Many a network has gone down by someone accidentally pulling out the plug to the file server. The same holds true for any other networking hardware as well. If anything supporting the network loses power, down it all comes.

It's also a good idea to protect the server with a UPS (uninterruptible power supply) so that if the power fails you can shut down the system properly. If the room will be staffed all the time, one of those $100 models will suffice. Otherwise look for a "server" model that has software to shut down the system if power is not restored within several minutes.

Don't overlook having up-to-date start up and maintenance disks ready to go in the event of hardware problems. Macintosh users can get these[1] by an anonymous ftp: ftp.support.apple.com/pub/apple_sw_updates/ US/Macintosh/System%20Software/System_7.5_Update_1.0/. Keep multiple copies of startup disks and utilities handy; if one disk g'es bad, you'll have another ready to go.

As a precaution, locate the file server away from the rest of the room, preferably in another room located next to the lab, like a locked closet. A file server sitting next to printers or computers that students use invites curious eyes and hands. Whatever you do, don't use this closet as a storage room. Allow the room's air to circulate. And don't pile supplies, like boxes of paper, around it. Later, when you need access, you don't want to have to move a lot of other things out of the way.

If you can't keep the server physically away from children then use a password-protected screen blanker. Make sure it's something simple; the animated graphics in most commercial screen savers will tie up the CPU and eat into network performance.

Use a big hard drive for the server. I like to have applications load off the server. It makes the computer "universal" so any child can run any application from any computer.

While networkable software may cost more initially, as the network grows, you can add additional users at no additional cost. In all cases check your software license to see how many computers can legally use it. The Administrator function of networks makes it easy to lock applications to a certain number of users.

Others prefer loading applications onto the local hard drive for speed reasons. In my lab, I use a mixture of both. I try out the application on the network and if it d'esn't work or is too slow I load it onto local drives.

If you can, buy only networkable software. It lets you use less expensive computers as workstations, and they won't need a large hard drive since only the files needed to start the workstation and networked programs are loaded.

Set up applications to install over the network even if you can't run them on the network. Every application I've ever tested on the Mac can be setup to install over AppleShare. This saves you from having to drag around a bunch of floppies to each machine.[2] When installing software, particularly new system software, install it on only one machine and monitor that machine for problems for several days.

Use SCSI hard drives in the file server. SCSI can queue multiple read/write requests for greater speed. Also, SCSI drives are available in greater capacity and higher RPM speeds. The faster the platters rotate on a hard drive, the more information can be put down or pulled off it. Another plus to SCSI is that it is as close to a universal expansion bus as you can get; one can connect up to seven devices to each SCSI card. With this configuration you can add additional hard disks, CD-ROMs, tape backup units, scanners and a variety of other devices to the server for just the cost of the device and a cable.

If your file server is going to be used for "mission critical" applications like an administrative network or students records, consider an external SCSI drive for all the network files. This way you can remove the drive from the file server, in case of a fatal system crash, and plug it into another machine. While your network may work slowly in this configuration, at least it's working. Test this setup before you really need to use it. Another technique is to have applications on a write-protected/read-only disk or partition and have documents stored on a read/write disk or partition. This way you can backup applications once and documents as frequently as needed.

Savvy graduate students make good onsite technical support people.

Get Others Involved

Start a computer club at the school. This shifts learning the mechanics of a computer to non-instructional time. Then, when the children come to the lab for a classroom assignment, they don't have to be taught how to use a mouse, etc. Also, students can help out their teachers with the in-classroom computers, which they are proud to do. Look for fun projects for the children.

Have an after-school keyboard class if state education laws prohibit teacher keyboarding/typing without a business teacher/typing teacher present.

You may want to consider evening classes for parents as well. Frequently, parents are at a loss when it comes to finding quality computer instruction for their family. College courses are often out of a working family's price range, although community colleges sometimes offer low-cost classes in popular software programs. Instruction at computer stores is often just as expensive. And all of those options are likely to have full enrollment. Local schools have a unique ability to offer instruction to families of students at affordable rates. Depending on your district, computer facilities and ambition, you could have a self-supporting computer program by offering computer classes at night in your labs.

Have an onsite technical person if possible. Look for that unique combination of people skills and computer expertise. If you can't find both, go with the people skills first as these are more difficult to come by. Many districts cannot fund a teaching position to run the lab, so by hiring a technician or network manager they get the onsite support for teachers and students. Ensure everyone is comfortable with the setup. Include the teachers' union, if there is one, in discussions. Everyone should know that this person is there to provide support, not to do the teacher's job. In the best arrangements of this type, the computer person gets a lot of support from the administration. Strive to achieve a peer-to-peer relationship between the computer support person and teachers.

The best people for this position, in my opinion, are computer-savvy graduate students. Undergraduate students are too close in age to students at middle or high schools, and frequently will have classes that prevent them from being in the lab for part of a day. Graduate students, on the other hand, often have classes after school hours or on weekends.

All prospective lab technicians should go through a screening process and receive clearance from the state police or FBI. In Pennsylvania this is known as Act 33/Act 34 clearance. Remember that these people will be working with your students and should behave accordingly.

Finally, a telephone in the lab is essential for reaching vendors' customer support staffs and for modem communications. If your school or district is concerned about costs, have the phone line restricted to prevent calling unauthorized numbers. With a phone in every lab, technicians in other buildings in your school district can help one another out.

The curriculum should drive the computer program, not the other way around.

Facilities Considerations

Allow room for other materials on computer tables. My tables are six feet long by two feet in depth. These are too small; the children have no room for their papers and the depth d'es not allow for connections on the back of the computers.

I've found that a 30-inch by 30-inch work area per computer works best in a lab situation. One way to decide how deep tables should be is to measure the size of the computer and add 18 inches to the depth.

Use a whiteboard instead of a blackboard -- computers and disk drives don't like chalk dust. A whiteboard can function as a projection screen as well, although I prefer to use a video adapter that displays a computer's output on a television set. With that set up, teachers can show the whole class how to do a new procedure or skill during class. Such adapters can also send output to a VCR to make instructional videotapes, which can then be played back in class before going to the lab, allowing children to see how to do what the teacher is asking.

Don't forget training for specific software packages. Show teachers how to fully utilize the programs they will be using with students. Whatever you do, don't assume that they'll just "get it."

Whenever your school gets new software, it's the job of the computer support person to install it, learn it and train teachers on its use. But don't overlook the training of your support staff as well, which should be the responsibility of veteran technicians. With new software or hardware, negotiate for training in the purchase.

Inservice training programs should be continual, not a one-shot deal where, if a teacher misses it, they're out of luck. Training needs to be on a yearly schedule to account for changes in professional staff. Always evaluate a training program to ensure the skills taught were mastered.

Notebook computers can be an effective tool for teacher training. Load the software they are interested in learning and teachers can take the computer home to learn at their leisure. During the day, with network monitoring software, technical support staff can perform diagnostic work on the network using the same machine.

Access Issues

If there will be several labs in a school district, connect them together for cooperative learning activities. This can be as simple as a modem on the lab's phone line, ISDN connection or as complex as a fiber optic link or T1 data line between all schools.

Include access to the Internet in your lab. Depending on your needs and goals, this could take the form of a dedicated Internet connection or several shared modems. Internet access is an issue all to itself, so I'll leave the subject by saying you need to have a mechanism in place that limits students access. You don't want children to use this resource without some sort of checks and balances. Two programs of potential benefit are SurfWatch and Net Nanny, offered in Mac and Windows versions. Other programs and approaches are available as well.

Sponsor a parents/community night after the lab is up and running and let both students and teachers show off their skills for visitors. Some members of the community, especially those without children in your schools, will view computers as an unneeded expense. Make sure the lab is open and operational during Open House. Have plenty of examples of student work on hand -- maybe some of the most skilled students can demonstrate their knowledge. Invite the media when you show off your lab; they love this kind of human interest stuff.

Planning & Budget Issues

Eight megabytes of RAM is essential to run today's software and operating systems. Minimum memory requirements listed on software boxes are typically for stand-alone machines, not a network, and networking software always takes up some memory. If memory is tight some packages won't run or will exhibit odd behavior. Having 8MB in the computers also saves you from having to resort to using virtual memory, a technique that uses a portion of the computer's hard drive to simulate memory. While it d'es work, performance takes a major hit.

When preparing a yearly budget, don't overlook the inevitable software upgrades. Evaluate upgrades as you would any other software purchase. If the application is a major part of your program then it's worth upgrading as older versions cannot usually read files created by newer versions. If a program is not integral, then sticking with an older version may be fine.

Use only Ethernet or other high-speed networking systems. LocalTalk (for Apple Macintosh) and other low-cost networking systems are just too slow to use with anything except small classroom clusters of computers or for printer sharing.

If you're extending your lab to classrooms, pull additional runs of network cable to each location. This has several advantages, the first being reduced labor costs. Indeed, 65% of the investment you make in wiring will be for labor, the rest will be for the cable. It will cost no more in labor to run four network cables into a classroom than it will to run two. In case you need to expand your network or a cable gets damaged, there is already a backup in place.

With Ethernet use only Category 5 wiring; while this will be more expensive than Category 3, you won't have to replace it to switch to a faster speed network.

Involve the professional staff early on. They will take ownership of the computer lab and network and want it completed. During planning, listen to what the teachers want. Make it clear that the district or school is behind this 100% and wants them to provide input as to direction and purpose. If teachers want small clusters in classrooms, give it to them. Remember that the purpose of a computer lab is to enhance the students' education. Whatever you do, it should be educationally sound. The curriculum should drive the computer program, not the other way around.

When planning, divide the budget into four broad categories: computers, networking, software and training. Use these figures to see where you will need to raise additional money or perhaps implement your program in stages. While every situation is different, this assures that essential items won't be overlooked.

Troubleshooting

When making changes, change only one thing at a time. That way you know what went wrong and can easily restore it back to the way it was.

Carefully document changes to the network and allow proper time to evaluate the impact. Once set up, most networks will run without needing any changes.

Performance can almost always be improved by judicious tweaking of certain parts of the networking software. Always record all settings before you begin and make backup copies of critical network files.

One way to improve network performance is to increase the memory allocated to the cache on the file server. However, be alert for the "plateau effect," where the server and network's performance plateaus and increasing memory to cache gains very little. Once you reach this, reduce the amount of memory allocated to the cache down to when the plateau begins to occur.

Often you will have no test equipment to help track down network problems. A tried-and-true method is the "divide & conquer" approach, which works with or without test equipment. Divide your network into smaller and smaller segments until the problem is isolated. Once the problem is solved, reconnect everything in reverse order that you took it apart and you're done.

A related technique is to drop machines off the network one by one until the problem g'es away. The machine you just took off the network is usually the culprit. Look for loose connections, cards not properly seated or breaks in network cables, especially around connections. Substitute the suspected faulty part with a known working one to determine if your prognosis is correct.

Use the Groups function of the networking software to cluster your users. On the Macintosh network at my school, there is a Children's Group (all computers in the lab) and a Teachers Group (all teachers in the building). Each teacher has their own private folder into which they save work. They can log into the LAN from any computer and work with their files.

Don't forget to set up a user for yourself and include it in each group. This way you can log in as a member of that group without having to ask someone to reveal their password. On my school's network, I made several users for myself that allow me to access different resources. If I'm working on a problem and get called away, the network is protected from "exploring" by students.

Philip Hess was computer technician for Seville Elementary School in North Hills School District in Pittsburgh, Pa. He is now student teaching at McIntyre Elementary, in the same district, and will earn his masters in Elementary Education in May 1996 from Duquesne University.
E-mail: [email protected]
Home page: www.nauticom.net/www/philip/

References:
1. Taken from Tidbits #266, a Macintosh newsletter delivered by Internet e-mail, published by Adam C. Engst. For more info, send e-mail to: [email protected]
2. Call (800) 505-0171 and request document # 20702, Apple's "Software Installation Over a Network" sheet.

Products mentioned in this article:
SurfWatch; SurfWatch Software, Inc., Los Altos, CA, (800) 458-6600, www.surfwatch.com
Net Nanny; Trove Investment Corp., Vancouver, BC, (800) 340-7177, [email protected]