In general, the students can tell whether or not the data is good or bad. They should have some expectation about what to expect, assuming that they have done their part to read the material, attend class and so on. For instance, they should have some expectation about the shape of a titration curve or of a first order decay. Furthermore, when curve-fitting is used, a correlation coefficient is calculated, which allows the student to see how much scatter or noise is in the data. The programming language is very basic and simple.
Any instructor ought to be able to learn how to program with little difficulty.
At this point, I cannot comment about the difficulty of programming from the students perspective since we are just starting to introduce LabWorks into our curriculum and have not yet required the students to design their own experiments. Learn More about LabWorks I encourage anyone who is interested in LabWorks to contact SCI Technologies. They will send you a system for evaluation. They also host numerous workshops throughout the year around the country. Our department attended a workshop this fall at Grossmont College and we found it quite useful.