Data-logging interfaces have developed quickly over the last five years to an extent that today's devices are generally reliable and easy to use and should give a good number of years of service. In terms of functionality there is not a great deal to choose between devices in equivalent categories, but do note which features you get for your money. You will, of course, want to make the best of your investment in data-logging equipment by getting as much productive use from it as possible.

Decide, first of all, where the equipment will be used. For use in the science lab, a serial-port interface will probably suit you; if you want to carry out data-logging away from a computer or if the technology department is involved in computer control, then you may consider a datalogger or a measurement and control interface. In either case, ensure that there is good software to support the computers which are in your school now and may be in the future.

You will be buying a data-logging system, not only a data-logging interface, but also a set of sensors, a computer connecting lead and software. The total cost needs to be taken into account. Ensure that your chosen system has the range of sensors which you will require; think in terms of a basic set of frequently-used sensors per interface plus one or two of the more expensive sensors. Most manufacturers offer some sort of starter kit.